Nanomedicine, Volume IIA: Biocompatibility
© 2003 Robert A. Freitas Jr. All Rights Reserved.
Robert A. Freitas Jr., Nanomedicine, Volume IIA: Biocompatibility, Landes Bioscience, Georgetown, TX, 2003
Glossary (see also Volume I Glossary)
Abscess – a circumscribed collection of pus appearing in acute or chronic localized infection, and associated with tissue destruction and frequently with swelling; a cavity formed by liquefaction necrosis within solid tissue.
Acetylcholine – a chemical neurotransmitter.
Acidosis – excessive acidity of body fluids due to acid accumulation or excessive bicarbonate loss.
ACTH – adrenocorticotropic hormone; stimulates adrenal gland cortex to produce adrenal cortical hormones.
Actin – structural protein derived from actomyosin in muscle and the most abundant protein in most cells, usually comprising more than 5% of the total cellular protein.
Acute – duration of less than 30 days; durations associated with clinical treatment are usually termed short-term or intraoperative . Compare chronic.
Adamantane – the smallest repeating cage unit of the diamond lattice (C10H16).
Adhesion antenna – in medical nanorobotics, partially selective binding tips that are swept through the environment, whereupon desired moieties or particles adhere and can be removed from the environment or drawn into the nanodevice (Section 10.4.2.5.2).
Adhesioregulatory – in medical nanorobotics, active regulation of the adhesive characteristics of the nanorobot surface (Section 188.8.131.52). See also sorboregulatory.
Adipose – fatty; pertaining to fat.
Adjuvant – in pharmacology, a drug added to a prescription to hasten or increase the action of a principal ingredient; in immunology, a variety of substances (e.g., alum, aluminum hydroxide, aluminum phosphate inorganic gels) that increase the antigenic response.
ADME – Absorption, Distribution, Metabolism, and Excretion screening tests for drug discovery . See also pharmacokinetics.
ADP – adenosine diphosphate; has one energy-rich phosphate bond.
Adrenergic – activated or energized by adrenalin (epinephrine).
Adsorption – adhesion of a substance to the surface of another material.
Aerobot – flying robot.
AFM – atomic force microscope.
Afferent – in relation to nerves or blood vessels, conducting toward structure or organ; carrying impulses toward a center, as when sensory nerves carry sensory information toward the brain or spinal cord.
Affinity – the strength of the binding of a ligand to a receptor, or the reciprocal of the dissociation rate constant; a measure of the binding energy of a ligand in a receptor; the greater the affinity, the more securely the receptor binds the ligand.
Agenesis – failure of an organ (or part thereof) to develop or grow.
Agglutination – one type of antigen-antibody reaction in which a solid antigen clumps together with a soluble antibody; often in reference to red blood cell typing.
Agonist – in pharmacology, a drug which binds to a receptor and thus stimulates the receptor’s function, possibly mimicking the body’s own regulatory function. Compare antagonist.
Agranulocyte – a nongranular leukocyte; see monocyte, lymphocyte.
Albumin – the most abundant blood protein.
Alginate – any salt of alginic acid; derived from kelp; used in pharmaceuticals, dentistry, and foods.
Alimentary – pertaining to the digestive tract.
Alkanethiol – a class of organic compounds which consist of a carbon chain (alkane) attached to a sulfur-based chemical group (thiol).
Allergen – any substance that causes manifestations of allergy.
Allergy – an acquired, abnormal immune response to a substance (allergen) that does not normally cause a reaction.
Alloantigen – a substance present in certain individuals that stimulates antibody production in other members of the same species, but not in the original donor.
Allodynia – a condition in which an ordinarily painless stimulus, once perceived, is experienced as being painful (Section 184.108.40.206).
Allogeneic – having a different genetic constitution but belonging to the same species.
Allograft – transplant tissue obtained from the same species as the host.
Alloknesis – a state of spinal sensitization, similar to secondary hyperalgesia/allodynia [3677, 5837], wherein strong itching stimuli induce a cutaneous halo and itchy skin in which innocuous light touch can easily elicit itch [5835, 5836]. Alloknesis depends on the magnitude of the inducing itch stimulus, is controlled by nociceptive input from the peripheral itch focus, and is fully blocked by cooling the itch focus [3677, 5838].)
Alloplast – inert implanted material, used in plastic surgery.
Allosteric control – the ability of an interaction at one site of a protein to influence the activity of another site.
Allotype (allotypic) – genetic variants of protein that occur in a single species; each variant can be antigenic to members of the same species possessing different variants.
Alveolus (alveolar) – in anatomy, a small cell or cavity; a saclike dilation. Most commonly, a small air sac found at the lowest levels of the branching tube system comprising the lungs.
Alveolitis – inflammation of alveolus.
Alzheimer’s disease – a chronic, organic mental disorder; a form of presenile dementia.
Amebiasis – infection with amebae.
Amniotic (amnion) – pertaining to the amnion (the innermost of the fetal membranes).
Amphipathic – molecular structures which have two surfaces or ends, one of which is hydrophilic and the other of which is hydrophobic. Lipids are amphipathic, and some protein regions may form amphipathic helices with one charged face and one neutral face.
Amphiphile – a molecule having both hydrophobic and hydrophilic components (e.g., soap).
Amphoteric – ability to react as both an acid and a base.
Amyloid(osis) – metabolic disorder marked by deposition of amyloid (a protein-polysaccharide complex) in tissues and organs.
Amyotrophic lateral sclerosis (ALS) – a syndrome marked by muscular weakness and atrophy due to degeneration of motor neurons of spinal cord, medulla, and cortex.
Analgesia – absence of normal sense of pain.
Analyte – sample substance whose chemical composition is being analyzed.
Anaphylaxis – the immediate transient kind of immunologic (allergic) reaction characterized by contraction of smooth muscle and dilation of capillaries due to release of pharmacologically active substances (e.g. histamine, bradykinin, serotonin, etc.); a powerful allergic response (Section 220.127.116.11). Anaphylaxis is classically initiated by the combination of antigen (allergen) with mast cell-fixed, cytophilic antibody (chiefly IgE immunoglobulin), but can also be initiated by relatively large quantities of serum aggregates (antibody-antigen complexes, and other) that seemingly activate complement leading to production of anaphylatoxin.
Anaphylatoxin – a substance composed of the C3 and C5 components of complement.
Anastomosis (anastomotic) – to open one structure into another directly or by connecting channels, usually said of blood vessels, lymphatics, and hollow viscera; to unite by means of an anastomosis, or a connection between formerly separate structures.
Anemia (anemic) – reduction in the number density of circulating red blood cells.
Anergic – unresponsive; inactive; lacking energy.
Aneurysm – localized abnormal dilation of a blood vessel, usually an artery, due to congenital defect or weakness in the vessel wall.
Angina pectoris – severe pain and sensation of constriction around the heart, caused by cardiac ischemia.
Angioedema – a condition characterized by development of urticaria (hives) and edematous (swollen with excessive fluid) areas of skin, mucous membranes, or viscera.
Angiogenesis – growth of new blood vessels, especially capillaries.
Angioplasty – altering blood vessel structure, either by a surgical procedure or by dilating the vessel using a balloon inside the lumen.
Anhydrobiotic – ability of an organism to survive almost complete desiccation.
Anion – a negatively charged ion; acidic. Compare cation.
Anophthalmic – congenital absence of one or both eyes.
Antagonist – in pharmacology, a drug that prevents receptor function. Compare agonist.
Anterior – the front of the human body, on or nearest the abdominal surface; the front of something.
Anterograde – moving frontward.
Anthrax – acute infectious disease caused by Bacillus anthracis.
Antibody – a protein (immunoglobulin) produced by B-lymphocyte cells that recognizes a particular foreign antigen, thus triggering the immune response (Section 18.104.22.168).
Anti-emetic – inhibiting vomiting.
Antigen – a foreign macromolecule capable of eliciting antibody formation; any molecule or foreign substance that, when introduced into the body, provokes synthesis of an antibody, thus stimulating an immune response; an agent that can bind specifically to components of the immune response; not all antigens are immunogens.
Antipyretic – reducing fever.
Antisense oligonucleotide – a nucleotide polymer having a sequence complementary to a target nucleotide sequence.
Aorta (aortic) – the largest artery in the human body, leading away from the heart.
Apheresis – removal of blood from an individual patient, separating certain elements (e.g. red cells, platelets, white cells) for use elsewhere, and reintroducing the remaining components into the patients; also known as cytapheresis, hemapheresis, leukapheresis, pheresis, and plasmapheresis, depending on the type of cells being harvested.
Apical – pertaining to the apex (e.g. the point of a cone) of a structure.
Apoptotic – undergoing apoptosis (programmed cell death).
Apoptosis – an orderly disintegration of eukaryotic cells into membrane-bound particles that may then be phagocytosed by other cells (Section 10.4.1.1).
Apposition – condition of being side by side or fitted together.
Aptamers – single-stranded nucleic acids that directly inhibit a protein’s function by folding into a specific three-dimensional structure that dictates high-affinity binding to the targeted protein .
Area compressibility modulus – a mechanical property characteristic of a membrane, defined as the isotropic tension per unit fractional change in area.
Aromatic compounds – in chemistry, ring or cyclic compounds related to benzene, many having a fragrant odor.
Arthropathy – any joint disease.
Arthroplasty – the operative procedure of reshaping
or reconstructing a diseased joint.
Artificial organ – a medical device that replaces, in whole or in part, the function of one of the natural organs of the human body.
Artificial organ, hybrid – an artificial organ that is a combination of viable cells and one or more biomaterials .
Ascites – accumulation of serous fluid in the peritoneal cavity.
Aseptic – characterized by the absence of living pathogenic organisms; a state of sterility.
Asialo- – a molecule lacking a sialyl group; see sialyl.
Aspiration – drawing in or out, as by suction.
Asperities – protruding elements of roughness on a surface, e.g., burrs or spurs.
Asplenic – without a spleen.
Asters – stellate rays forming around the dividing centrosome during mitosis.
Asthma – disease caused by increased responsiveness of the tracheobronchial tree to various stimuli, with paroxysmal constriction of the bronchial airways.
Astrocyte – a star-shaped neuroglial cell with many branching processes.
Astroglioma cells – neoplastic or tumor cells associated with astrocytes making up neuroglial tissue.
Atelectasis – condition in which fetal lungs remain unexpanded at birth.
Atherectomy – a procedure to remove plaque from arteries; e.g., using a laser catheter or a rotating “burr” shaver.
Atherosclerosis (atherosclerotic) – the most common form of arteriosclerosis (thickening, hardening, and loss of elasticity of arterial walls).
ATP – adenosine triphosphate; has two energy-rich phosphate bonds.
Atrial natriuretic peptide – hormone secreted by atrial tissue of the heart in response to an increase in blood pressure.
Atrium (atrial) – chamber or cavity communicating with another structure.
Atrophy – decrease in size of organ or tissue; to waste away.
Auricle – portion of the external ear not contained within the head; the pinna.
Austenitic – a higher-temperature body-centered cubic structure with the characteristic stress-strain curve of most metals; compare martensitic.
Autocatalysis (autocatalytic) – increase in the rate of chemical reaction resulting from products that are produced in the reaction acting as catalysts.
Autologous – having its origin within the host organism.
Autolysis – self-dissolution or self-digestion of tissues or cells, by endogenous enzymes.
Autophagy – self-consumption by a cell.
Autosome (autosomal) – any of the chromosomes other than the XY sex chromosomes.
Avirulent – without virulence.
Azurophilic – staining readily with azure dye.
Babesiosis – a rare and often severe or fatal disease of man caused by an intraerythrocytic protozoan, Babesia microti, transmitted by ticks.
Bacteremia (bacteremic) – bacteria in the blood.
Bacteriophages – viruses that infect selected bacteria; often abbreviated as phages.
Barosensor – pressure-detecting sensors in cells.
Basal lamina – basement lamina, e.g. basement membrane.
Basal rate – in metabolism, a measure of the metabolic rate taken with the patient fasting and at rest. The oxygen consumed in breathing under these conditions indicates the minimum rate of chemical reactions in the body.
Basement membrane (basement lamina) – a thin layer of delicate noncellular material of a fine filamentous texture underlying the epithelium; its principal component is collagen.
Base pair (bp) – a complementary purine-pyrimidine hydrogen-bonded residue pair, one from each strand of DNA double helix, designating one unit (bp) of sequence. A partnership of adenine (A) with thymine (T) or of cytosine (C) with guanine (G) in a DNA double helix; other pairs can be formed in RNA under certain circumstances.
Basophil – a type of granulocytic white blood cell comprising less than 1% of all leukocytes, that is essential to the nonspecific immune response to inflammation because of its important role in releasing histamine and other chemicals that act on blood vessels.
Biliary – pertaining to bile.
Billroth’s cords – splenic cords found in the red pulp between the sinusoids, consisting of fibrils and connective tissue cells with a large population of monocytes and macrophages.
Bioactive – the ability of a biomaterial surface or coating to adhere directly to soft or hard tissue without an intermediate layer of modified tissue .
Bioactive material – a biomaterial that is designed to elicit or modulate biological activity ; Section 22.214.171.124.
Bioadhesion – the adhesion of cells or tissue to the surface of a material .
Bioattachment – the fastening of cells or tissue to the surface of a material, including mechanical interlocking .
Biocompatibility – biological performance in a specific application that is judged suitable to that situation ; the ability of a material to perform with an appropriate host response in a specific situation .
Biocompatible material – one having acceptable host and material response in a specific application .
Biodegradation – the breakdown of a material mediated by a biological system ; the passive response of a material to the physico-chemical conditions found in living systems, involving actual cellular effects on the pericellular environment .
Biodistribution – distribution of a substance, after in vivo administration, throughout the organs and tissues of the body.
Biofilm – bacteria embedded in a film of adhesive polymer (especially on implanted devices); bacteria within the film are protected from the action of antibiotics (Section 126.96.36.199).
Biological performance – the interaction between materials and living systems ; preferred term is biocompatibility.
Biomaterial – a material intended to interface with biological systems to evaluate, treat, augment, or replace any tissue, organ, or function of the body ; a nonviable material used in a medical device, intended to interact with biological systems .
Biomaterials, inert – implantable materials that elicit little or no host response .
Biomaterials, interactive – implantable materials designed to elicit specific, beneficial responses, such as ingrowth, adhesion, etc. .
Biomaterials, replant – implantable materials consisting of native tissue, cultured in vitro from cells obtained previously from the specific implant patient .
Biomaterials, viable – implantable materials, incorporating or attracting live cells at implantation, that are treated by the host as normal tissue matrices and are actively resorbed or remodeled .
Biomaterials engineering – the application of the principles of biomaterials science and its foundation sciences to the solution of practical problems of human health, disability, and disease .
Biomaterials field – the organized study of the materials properties of the tissues and organs of living organisms; the development and characterization of pharmacologically inert materials to measure, restore, and improve function in such organisms; and the interaction between viable and nonviable materials . Biomaterials is: (1) a materials science, the central issue being the dependence of physical properties on composition and structure; (2) an interdisciplinary science, its unique feature being a consideration of the interactions between living and nonliving materials; and (3) a medical science, whose ultimate goal is the improvement of human health and quality of life .
Biomaterials science – the study and knowledge of the interaction between living and nonliving materials .
Biomimetic – an approach to bioengineering in which artificial materials are selected to mimic as closely as possible the desired structure or function of natural biological components.
Bioresorbable – the ability of a biomaterial to be digested by or as a consequence of cellular activity, and thus dissolve or disappear in part or in whole after implantation; implies specific action of cells or tissues . See also resorbable.
Blockade – prevention of the action of something, such as the effect of a drug or of a body function, e.g. halting immune system blood cleansing by overloading the RES (Section 188.8.131.52.10).
B-lymphocytes (B-cells) – thymus-independent white blood cells responsible for synthesizing antibodies.
Bolus – mass of masticated food ready to be swallowed; concentrated mass of a diagnostic substance given rapidly intravenously.
Bone bonding – the establishment, by physicochemical processes, of continuity between implant and bone matrix .
Bowman’s capsule – a visceral layer closely applied to the glomerulus and an outer parietal layer that functions as a filter in the formation of urine in the kidney.
bp – see base pair.
Brachiation – in medical nanorobotics, by alternately swinging the arms (e.g. swinging hand-over-hand).
Brachymetatarsia – abnormal shortness of one of the metatarsals (the five long bones of the foot), resulting in a short toe.
Bradykinin – an end product of contact system activation (Section 15.2.5).
Bronchoconstriction – constriction of the bronchial tubes.
Broncholithiasis – bronchial inflammation or obstruction caused by calculi in the bronchi.
Bronchopulmonary – pertaining to bronchi and lungs.
Bronchus (bronchi) – one of the two large branches of the trachea.
Brownian motion – random motion of small particles in a fluid owing to thermal agitation.
BSA – bovine serum albumin. See also albumin.
Buckyballs – ball-like molecules of fullerene carbon, C60 (Section 2.3.2).
Buckytubes – carbon nanotubes (Section 2.3.2).
Calciphylaxis – state of induced tissue sensitivity characterized by calcification of tissue when challenged by an appropriate stimulus.
Calculus (calculi) – commonly called stone; any abnormal concretion within the animal body, though usually composed of mineral salts.
Calmodulin – a 17,000-dalton protein that binds calcium ions in eukaryotic cells, thereby becoming the agent for many or most of the cellular effects ascribed to calcium ions.
Calor – local tissue temperature rise, one of the four classic signs of inflammation (Section 15.2.4); see also dolor, rubor, tumor.
cAMP – cyclic AMP (adenosine monophosphate), an intracellular messenger molecule.
Canaliculus (canalicular) – small channel or canal.
Cancer – a disease of multicellular organisms characterized by uncontrolled multiplication and spread of abnormal forms of host cells .
Canine – pertaining to dogs.
Cannula – tube or sheath enclosing a trocar (a transdermal punch), the tube allowing escape of fluid after withdrawal of the trocar from the body.
Capacitance, electrical – ability to store electric charge.
Capacitance, phagocytic – ability of phagocyte to ingest phagocytic targets.
Capillaritis – inflammation of the capillaries.
Capsule – tissue surrounding an implant produced by local host response . See also granuloma, incapsulation.
Carbon black – finely divided amorphous carbon particles (Section 184.108.40.206).
Carcinogen – an agent capable of causing cancer (Section 15.2.8).
Carcinoma – a new growth or malignant tumor that occurs in epithelial tissue; can metastasize throughout the body.
Cardiac – pertaining to the heart.
Cardiomegaly – abnormal enlargement of the heart.
Cardiomyopathy – disease of the myocardium (heart muscle).
Cardioplegia – intentional arrest of the cardiac function using cold, electrical stimuli, or medication to greatly reduce the need of the myocardium for oxygen; often done during cardiopulmonary bypass.
Carotid – principal arteries supplying oxygenated blood to the head and neck, originating in the aorta.
Cartilage – specialized type of dense connective tissue consisting of cells embedded in a firm, compact fibrous collagenous matrix.
Catheter – a tube passed through the body for evacuating or injecting fluids into body cavities.
Cation – a positively charged ion. Compare anion.
Caveolae – structural indentations (~50 nm) in plasma membrane of the cell, serving to draw substances such as vitamins and signal transduction molecules into the cell’s interior.
Cavitation – in physics, the formation of bubbles in a fluid during high-power sonication of that fluid; in medicine, formation of a cavity by either normal or pathological biological processes. See Section 6.4.1.
CB – see carbon black.
CD- – cluster of differentiation, designating surface marker proteins that distinguish various T cell subpopulations (Section 220.127.116.11.2).
Cecum – a blind pouch that forms the first portion of the large intestine, located below the entrance of the ileum at the ileocecal valve (Figure 8.16).
Celiac – pertaining to the abdominal regions.
Cellulitis – inflammation of cellular or connective tissue, spreading as in erysipelas.
Centrosomes – the regions from which microtubules are organized at the poles of a mitotic (dividing) cell.
Ceramide – a class of lipids, derived from a sphingosine (a long-chain base present in sphingolipids), that do not contain cholesterol.
Cervix – the neck, or part of an organ resembling the neck; usually refers to neck of the uterus.
CFRC – carbon fiber-reinforced carbon.
CFU – colony forming units (e.g., number of microbes).
Chaotropic agents – structure-breaking ions, salts, and other agents that weaken hydrophobic associations, denature proteins, increase membrane permeability to protons, and can promote cell lysis.
Charcot-Marie-Tooth disease – a form of progressive neural muscular atrophy.
Chelation – combining of metallic ions with certain heterocyclic ring structures so that the ion is held by chemical bonds from each of the participating rings; chelating agents are commonly used to remove toxic metals from the body.
Chemisorption – adsorption with the formation of tight covalent bonds.
Chemokines – compounds that draw cells and other factors to sites of injury in the body.
Chemokinesis – general random movement or nondirected cell locomotion.
Chemorepellents (chemorepulsion) – chemotaxis antagonists or negative chemokinesis agents.
Chemotactic – pertaining to chemotaxis.
Chemotaxis – the movement of additional white blood cells to an area of inflammation in response to the release of chemical mediators by neutrophils, monocytes, or injured tissue; orientation or movement of cells toward a chemical source; movement along a spatial gradient or directed cell locomotion.
Chiggers – six-legged larvae of mites of the family Trombiculidae; redbugs.
Chimeric molecule – combining in one molecule dissimilar components from two or more different molecules.
Cholesterol – a sterol (a group of substances related to fats) widely distributed in animal tissues; a monohydric alcohol with a cyclic nucleus.
Cholinergic – activated or energized by acetylcholine.
Cholelithiasis – formation or presence of calculi or bilestones in the gallbladder or common duct.
Chondrocyte – a cartilage cell.
Chondrogenesis – formation of cartilage.
Chorioamnionitis – inflammation of the membranes that cover the fetus.
Chomatin – the complex of DNA and protein in the nucleus of the interphase eukaryotic cell; individual chromosomes cannot be distinguished in it.
Chronic – duration of 30 days or longer . Compare acute.
Chrysotile – a flexible, chemically-resistant, nonflammable fibrous mineral with high tensile strength.
Chylomicron – submicron-sized protein-lipid aggregates produced by the intestine and carried by the lymph system into the blood (Section 18.104.22.168).
Chyme – a semifluid mixture of partly digested food and digestive secretions found in the stomach and small intestine during digestion of a meal.
Circadian – pertaining to physiological events that occur at approximately 24-hour intervals.
Circumvascular – surrounding or wrapping around the exterior of a blood or lymph vessel.
Cirrhosis (cirrhotic) – a chronic liver disease involving loss of functioning liver cells, increased resistance of blood flow through the organ, and disturbance of normal tissue architecture; in serious cases, leads to ammonia toxicity.
Clathrin – cell-type specific 180,000-dalton protein that coats intracellular transport vesicles, forming a basket or cage around the vesicle. See vesicles (endocytotic).
Clinical – founded on actual observation and treatment of patients, as distinguished from data or facts obtained by experimentation or pathology; or, pertaining to a clinic.
Clottocytes – in medical nanorobotics, artificial mechanical platelets  (Chapter 24).
CNS – central nervous system.
Coagulation – sequential process in blood leading to thrombus formation (Section 15.2.5).
Coagulopathy – defect in the blood clotting mechanisms.
Coarctation – compression of the walls of a vessel; a stricture.
Cochlea (cochlear) – the coiled, fluid-filled structure of the inner ear that transduces sound, allowing hearing.
Colitis – inflammation of the colon.
Collagen – the major protein of the white fibers of connective tissue, cartilage, and bone, rich in glycine, alanine, proline, and hydroxyproline (amino acids), low in sulfur, and completely lacking in tryptophan (another amino acid); the collagen family comprises ~25% of all mammalian protein.
Collagenase – an enzyme that catalyzes the hydrolysis of collagen.
Colon (colonic) – the large intestine (Figure 8.16).
Colostrum – breast fluid that may be secreted from the second trimester of pregnancy onward, preceding true lactation.
Commissure – the coming together across the midline or dividing space of two structures.
Communicyte – in medical nanorobotics, a theorized mobile, mass-storage (nanorobotic) device that can be used for information transport throughout the human body (Section 7.3.2).
Complement – a group of proteins in the blood that influences the inflammatory process and serves as the primary mediator in the antigen-antibody reactions of the B-cell mediated immune response. Components of complement are labeled C1-C9; C3 and C5 are most commonly involved in promoting vasodilation, chemotaxis, opsonization of antigens, lysis of cells, and blood clotting (Section 22.214.171.124).
Compliance, mechanical – the reciprocal of stiffness; in a linear elastic system, displacement equals force times compliance.
Concussion (concussive) – injury resulting from impact with an object.
Condyle – a rounded protuberance at the end of a bone forming an articulation.
Conformation – molecular folding; a molecular geometry that differs from other geometries chiefly by rotation about single or triple bonds; distinct conformations (termed conformers) are associated with distinct potential wells. Typical biomolecules and products of organic synthesis can interconvert among many conformations. Typical diamondoid structures are locked into a single potential well, and thus lack conformational flexibility.
Congestive heart failure – weakness, breathlessness, abdominal discomfort and lower-body edema resulting from venous stasis and reduced outflow of blood from the left side of the heart.
Conjugated – in chemistry, a conjugated pi system is one in which pi bonds alternate with single bonds; the resulting electron distribution gives the intervening single bonds partial double-bond character, the pi electrons become delocalized (useful in molecular wires), and the energy of the system is reduced. More generally, joined or paired.
Control material – see reference material.
Contusion – injury in which skin is not broken; bruise.
Cornea – the clear, transparent anterior portion of the fibrous coat of the eye comprising about one-sixth of its surface.
Coronary – refers to the heart and to coronary heart disease; encircling the heart.
Corpus callosum – the great commissure of the brain between the cerebral hemispheres.
Cortex (cortical) – the outer layer; compare medulla.
Costimulatory – costimulatory molecules are required on a target surface (e.g., of a cell to be phagocytosed) before T cells may become activated.
Costochondral – pertaining to a rib and its cartilage.
Covalent bond – in chemistry, a bond formed by sharing a pair of electrons between two atoms.
Cranium (cranial) – pertaining to the portion of the skull enclosing the brain.
Creatinine – end product of creatine metabolism, found in urine; increased quantities indicate advanced stages of renal disease.
Cricothyroid – pertaining to the thyroid and cricoid cartilages.
Crinal – pertaining to hair.
Crosslinks – in biochemistry, additional bonds formed between normally separate parts of a polymer, typically increasing the tensile strength and stiffness of the chain.
Cruciate – cross-shaped.
Crystallescence – in medical nanorobotics, the crystallization of solid solute that is offloaded by nanorobot sorting rotors at a concentration that exceeds the solvation capacity of the surrounding solvent (Section 9.2.6).
Crystalluria – appearance of crystals in the urine.
CSF – cerebrospinal fluid.
Cutaneous – pertaining to the skin.
CVD – chemical vapor deposition.
Cyanosis – bluish or grayish skin discoloration due to abnormal amounts of reduced hemoglobin in the blood.
Cycloaddition – a chemical synthesis reaction in which two unsaturated molecules (or moieties within a molecule) bond to form a ring.
Cystic fibrosis (CF) – inherited disease of exocrine glands characterized by chronic respiratory infection, pancreatic insufficiency, and increased electrolytes in sweat.
Cytoambulation (cytoambulatory) – in medical nanorobotics, cell surface walking (Section 9.4.3).
Cytocarriage – in medical nanorobotics, the commandeering of a natural motile cell, by a medical nanorobot, for the purposes of in vivo transport (of the nanorobot), or to perform a herding function (of the affected cell), or for other purposes (Section 9.4.7).
Cytochrome – a class of cellular respiration hemoprotein pigments.
Cytocide – the killing of living cells (Section 10.4).
Cytocompatibility – biocompatibility with cells.
Cytokines – a group of extracellular biochemical substances that may be produced by a variety of cells, for the purposes of chemical messaging, regulation, and control; proteins that exert changes in the function or activity of a cell, such as differentiation, proliferation, secretion, or motility; chemical species used for intercellular signaling .
Cytopathology – pathology of the cell.
Cytopenetration – in medical nanorobotics, entry into cells by penetrating the plasma membrane (Section 9.4.5).
Cytoplasmic – pertaining to, or residing in, the cell cytoplasm.
Cytoskeleton – the internal structural framework of a cell consisting of at least three types of filaments (microfilaments, microtubules, and intermediate filaments), forming a dynamic framework for maintaining cell shape and motion and allowing rapid changes in the three-dimensional structure of the cell (Section 126.96.36.199).
Cytosurgery – surgical procedures performed on individual cells.
Cytotoxic – having a deleterious or adverse effect on cells, up to but not always implying cell death; tending to kill cells.
Dacron – polyethylene terephthalate.
Dalton – unit of molecular weight (1 dalton ~ 1 proton).
Decubitus – a bedsore.
De-differentiation – the loss by mature cells of some of their specialized properties and reversion to a less developed state . De-differentiation is a normal part of healing and regeneration , can be induced mechanically , and is often a part of early tumor development . Artificial de-differentiation, or cellular reprogramming, aims at getting specialized body cells to revert to a primordial state, like stem cells, so they can be turned into various types of tissues .
Degranulation – loss of granules, especially in a phagocytic cell.
Denaturation – conversion of a protein from the physiological conformation to some other (possibly inactive) conformation.
Dendrimers – large, regularly-branching molecules (Section 188.8.131.52).
Dendrite – a branched protoplasmic process of a neuron that conducts impulses toward the cell body. There are usually many to a cell, forming synaptic connections with other neurons.
Dendritic cells (DCs) – leukocytes of bone marrow origin; antigen presenting cells scattered throughout the body in immature form as immunological sensors; subsets of DCs differ in phenotype, function, and locale.
Denudation – removal of a protecting layer or covering through surgery, pathological condition, or trauma.
Deoxyribonucleic acid (DNA) – a complex molecule of very high molecular weight encoding genetic information. DNA consists of deoxyribose (a sugar), phosphoric acid, and four bases (purines or pyrimidines), arranged as two long chains that twist around each other to form a double helix joined by bonds between the complementary purine and pyrimidine components (analogous to rungs on a twisted ladder). DNA is present in the chromosomes of all cells and is the chemical basis of heredity and the carrier of genetic information for almost all organisms (e.g. except the RNA virus, etc.).
Dermatitis – inflammation of skin evidenced by itching, redness, and various skin lesions.
Dermis – inner layer of the skin that lies below the epidermis.
Desialylated – molecules from which sialyl chemical groups have been removed.
Desiccate – removal of water; dehydration.
Detritus – broken down or degenerative matter produced by disintegration.
Device, medical – an instrument, apparatus, implement, machine, contrivance, in vitro reagent, or other similar or related article, including any component, part, or accessory, intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease in humans .
Dialysate – a fluid that has been dialyzed.
Dialysis (dialyzer) – the passage of a solute through a membrane; process of diffusing blood across a semipermeable membrane to remove toxic materials and to maintain fluid, electrolyte, and acid-base balance in cases of impaired kidney function.
Diamondoid – structures that resemble diamond in a broad sense; strong, stiff structures containing dense, three-dimensional networks of covalent bonds, formed chiefly from first and second row atoms with a valence of three or more. Many of the most useful diamondoid structures will be rich in tetrahedrally coordinated carbon.
Diapedesis – transendothelial migration (passing through blood vessel endothelial coated walls) to exit the bloodstream and enter the surrounding tissues (Section 184.108.40.206).
Diaphysis – the shaft or middle part of a long cylindrical bone.
Diastole (diastolic) – the normal period in the heart cycle during which the muscle fibers loosen and lengthen, the heart dilates, and the cavities fill with blood; roughly, the period of relaxation alternating with systole or contraction.
Diathermy – local elevation of temperature within the tissues, produced by high-frequency (~MHz) current, ultrasonic waves, or microwave radiation.
DIC – see disseminated intravascular coagulation.
Dielectrophoresis – the lateral motion imparted on uncharged particles as a result of polarization induced by non-uniform electric fields.
Differentiation – acquisition of character or functions that are different from those of the original type; specialization of cell type within a cell line of increasingly specialized types, by a change in physical form of a cell.
Diffusion – a process by which populations of molecules intermingle and become mixed as a result of their incessant thermal motions.
Disseminated intravascular coagulation (DIC) – a pathological form of coagulation that is diffuse rather than localized (as in normal coagulation), with several clotting factors so heavily consumed that generalized bleeding may occur.
Disse space – fluid-filled space outside hepatic endothelial cells (Figure 8.27).
Distal – away from a source or a point of attachment or origin; in the extremities, farthest from the trunk.
Diverticulum – a sac or pouch in the walls of a canal or organ.
DLC – diamond-like carbon.
DNA – see deoxyribonucleic acid.
Dolor – local pain, one of the four classic signs of inflammation (Section 15.2.4); see also calor, rubor, tumor.
Dopaminergic – activated or energized by dopamine.
Dorsal – pertaining to the backside.
Duodenum – the first ~12 inches of the small intestine.
Dura mater – outer membrane covering the spinal cord and brain.
Dust cells – alveolar macrophages.
Dysentery – intestinal disorders, especially of the colon, characterized by inflammation of the mucous membrane.
Dysesthesia – abnormal sensations on the skin, including feelings of numbness, tingling, prickling, burning, or cutting pain.
Dysopsonic – tending to remove opsonization molecules that have become adhered to an exposed in vivo surface.
Dysphonia – difficulty in speaking; hoarseness.
Dystrophia (dystrophic) – disorder caused by defective nutrition or metabolism.
EAG – “ether a go-go,” a distinct type of voltage-activated potassium (K+) channel.
EC – endothelial cells.
Ecchymosis – skin discoloration consisting of large, irregularly formed hemorrhagic areas, caused by extravasation of blood into skin or mucous membrane.
Eclampsia – Coma and compulsive seizures between the 20th week of pregnancy and the end of the first week postpartum; usually fatal if untreated.
ECM – see extracellular matrix.
Edema (edematous) – swollen with excessive fluid.
Edentulous – without teeth.
Efferent – in relation to nerves or blood vessels, conducting away from a structure or organ; carrying impulses away from a center, as when motor nerves carry impulses from the brain and spinal cord to an effector (e.g., a muscle).
Effervescence – in medical nanorobotics, bubble formation by a gaseous solute that is offloaded by nanorobot sorting rotors at a concentration that exceeds the solvation capacity of the surrounding solvent (Section 9.2.6).
Effluent – discharged fluid material; a flowing out.
Elasticity – a property of an object or material, wherein the object or material returns to its original shape after a force is applied and then removed.
Elastin – extracellular connective tissue protein; principal component of elastic fibers.
Electret – a material that retains a permanent charge.
Electrocautery – cauterization (destruction of tissue) by heated wire.
Electrochemistry – science of chemical changes produced by electricity.
Electrocompatibility – the electrical biocompatibility of nanodevices or nanorobotic systems as they interact with the organs, tissues and cells of the human body (Section 15.5.6).
Electrolyte – a substance that, in solution, conducts an electric current and is decomposed by the passage of an electric current; a solution that is a conductor of electricity.
Electron affinity – the energy liberated when an extra electron is attached to an atom to form an anion.
Electronegativity – a measure of the tendency of an atom (or moiety) to withdraw electrons from structures to which it is bonded. In most circumstances, sodium (Na) tends to donate electron density (low electronegativity) whereas fluorine (F) tends to withdraw electron density (high electronegativity); nitrogen (N) and oxygen (O) are also electronegative atoms.
Electrophoresis – the movement of charged colloidal particles through the medium in which they are dispersed as a result of changes in electrical potential; used in the analysis of protein mixtures because protein particles move with different characteristic velocities dependent principally on the number of charges carried by each particle.
Electroporation – insertion of macromolecules (e.g. DNA) into cells by employing a brief intense pulse of electricity to open cellular pores.
Electrostatic – pertaining to the static electric fields produced by charged objects.
Elliptocytosis – increased number of elliptocytes (oval-shaped red blood cells); occurs in some forms of anemia.
Elution – in chemistry, separation of one material from another by washing.
Embolus – a mass of undissolved matter (solid, liquid, or gaseous) present in a blood or lymphatic vessel, brought there by the blood or lymph current.
Emesis – vomiting; may be chemically induced using an emetic.
Emetogenesis – eliciting vomiting (Section 220.127.116.11).
Emperipolesis – temporary presence of one cell within another’s cytoplasm.
Encapsulation – formulation of granulation tissue with a fibrotic capsule surrounding the foreign body.
Encephalitis – inflammation of the brain.
Endarterectomy – surgical removal of the lining of an artery.
Endocarditis – a life-threatening inflammation of the heart’s inner lining.
Endocardium – serous lining membrane of the inner surface and cavities of the heart.
Endocytosis (endocytotic) – a process by which proteins arriving at the surface of a cell are internalized, being transported inside the cell within membranous vesicles.
Endogenous – originating inside an organ, part, or system.
Endohedral – lying entirely within a (fullerene) cage molecule.
Endometrium (endometrial) – pertaining to the lining of the uterus.
Endoplasmic reticulum – in cell biology, a highly convoluted sheet of membranes, extending from the outer layer of the nuclear envelope into the cytoplasm (Section 18.104.22.168).
Endoprosthesis – an internally-worn permanently-attached device that replaces a limb, organ, or tissue of the body . See also prosthesis.
Endoscopy – inspection of body organs or cavities using the endoscope (device consisting of a tube and optical system).
Endosome – the vacuole formed when material is absorbed into a cell by the process of endocytosis; the vacuole fuses with lysosomes.
Endosteum (endosteal) – membrane lining the medullary cavity of a bone.
Endosymbiont (endosymbiotic) – an organism or cell that lives inside another organism or cell, in a state of symbiosis.
Endothelium – a form of squamous epithelium consisting of flat cells (endothelial cells) that line the blood and lymphatic vessels, the heart, and various other body cavities.
Endotoxin – bacterial toxin confined within the body of a bacterium, freed only when the bacterial cell wall is lysed.
Endotracheal – within the trachea.
Enophthalmos – recession of eyeball into orbit.
Enteric – pertaining to the small intestine.
Enterocyte – intestinal (duodenum and jejunum) lining cells, important in the final phases of digestion and for absorption of protein, fat and carbohydrate.
Enterotoxin – toxin produced in or originating in the intestinal contents, exotoxin specific for the cells of the mucosa, or exotoxin produced by bacteria that cause food poisoning and toxic shock syndrome.
Enthalpy – in thermodynamics, the internal energy of a system plus the product of its volume and the external pressure.
Entropy – in the physical sciences, a measure of uncertainty regarding the state of a system; free energy can be extracted by converting a low-entropy state to a high-entropy state. In other contexts, the term is often used by analogy to describe the extent of randomness and disorder in a system and the consequent lack of knowledge or information about it.
Enucleated cell – a cell from which the nucleus has been removed.
Envasculoided – permeated with a vasculoid  appliance implant.
Enzyme – a protein molecule that often acts as a specific catalyst, facilitating specific chemical or metabolic reactions necessary for cell growth and reproduction; a biological chemosynthetic molecular machine.
Eosinophil – a type of granulocytic white blood cell comprising 1%-4% of all leukocytes, that is known to destroy parasitic organisms and to play a major role in allergic reactions (some of the major chemical mediators that cause bronchoconstriction in asthma are released by eosinophils).
EPA – Environmental Protection Agency (U.S.).
Epidermis (epidermal) – the outer epithelial portion of the skin.
Epidermalgia – sensation of pain in the epidermis (Section 22.214.171.124).
Epidural – located over or upon the dura.
Epimysium (epimysial) – outermost sheath of connective tissue that surrounds a skeletal muscle.
Episclera (episceral) – outermost superficial layer of the sclera of the eye.
Epithelium (epithelial tissue) – the avascular layer of cells forming the epidermis of the skin and the surface layer of mucous (secreting mucus) and serous (secreting serum or serumlike fluid) membranes, including the glands. The cells rest on a basement membrane and lie closely approximated to each other with little intercellular material between them. Skin and the lining of natural internal body cavities .
Epitope – the particular site on the macromolecular surface of an antigen which elicits specific affinity of an antibody; the antigenic determinant; any component of an antigen molecule that functions as an antigenic determinant by permitting the attachment of certain antibodies.
ER – emergency room.
Erysipelas – acute febrile disease with localized inflammation, with redness of skin and subcutaneous tissue accompanied by systemic signs and symptoms.
Erythema – redness; see rubor (inflammation).
Erythroblastosis fetalis – a hemolytic disease of the newborn characterized by anemia, jaundice, enlargement of liver and spleen, and generalized edema.
Erythrocyte – red blood cell.
Erythropathy – disease of the red blood cells.
Erythropoietic – producing erythrocytes.
Erythropoietin – a hormone that controls the production rate of red blood cells in the human body.
Esophagus (esophageal) – muscular canal extending from pharynx to stomach.
Esthesiometer – device for measuring tactile sensitivity.
Ethmoidal – pertaining to ethmoid bone (spongy bone forming roof for the nasal fossae and part of floor for anterior fossa of the skull) or sinuses.
Eukaryote (eukaryotic) – an organism or cell that contains its genome within a nucleus.
Euler buckling – force required to cause a structure to buckle under compression.
Euvolemic – normal blood volume.
Exocrine – external secretion of a gland; glands whose secretion reaches an epithelial surface either directly or through a duct.
Exocytosis (exocytic) – the process of secreting proteins from a cell into the surrounding medium, by transport in membranous vesicles from the endoplasmic reticulum, through the Golgi, to storage vesicles, and finally (upon a regulatory signal) through the plasma membrane.
Exogenous – originating outside an organ, part, or system.
Exoprosthesis – an externally-worn device that replaces a limb, organ, or tissue of the body. See also orthosis.
Exsanguinate – loss of blood to the point at which life can no longer be sustained; expressing blood from a part.
Extracellular – outside of the cell.
Extracellular matrix (ECM) – an extracellular fibrous scaffolding that helps organize cells into tissues (Section 126.96.36.199).
Extrahepatic – outside the liver.
Extranuclear – outside the cell nucleus.
Extravasation – exiting the bloodstream; see diapedesis.
Extravascular – outside a vessel.
Extrusion (implants) – resolution of inflammation, in which implants in contact with epithelial tissue are surrounded by a down-growing extension of such tissue, directed toward extruding the implant from the body; also termed marsupialization, due to the resemblance of the newly formed tissue to a kangaroo’s pouch .
Exudate – accumulation of a fluid in a cavity; matter that penetrates through vessel walls into adjoining tissue; the production of pus or serum.
Ex vivo – outside of the living human body.
Fabrey’s disease – an inherited metabolic disease in which a glycolipid (ceramide trihexoside) accumulates in the organs and tissues, impairing function of kidneys and other organs.
Fascia – a fibrous membrane covering, supporting, and separating muscles; also, unites the skin with underlying (e.g. muscular) tissue.
Fascicles – a small bundle, especially of nerve fibers.
FBGC – multinuclear foreign body giant cell.
FDA – Food and Drug Administration (U.S.).
Febrile – pertaining to fever (Section 15.2.7).
Feline – pertaining to cats.
Femur (femoral) – thigh bone; longest and strongest bone in human skeleton.
Fenestrated – having openings.
FEP – fluorinated ethylene propylene (a form of Teflon).
Ferrofluid – a stable colloidal liquid-carrier suspension of sub-domain magnetic particles of average size ~10 nm that are coated with a stabilizing dispersing agent (surfactant) to prevent particle agglomeration even when a strong magnetic field gradient is applied.
Fetotoxic – toxic to the fetus.
Fibrinogen – a blood protein molecule that is ultimately converted to the active protein, fibrin, after foreign surface contact during blood clotting (Section 15.2.5).
Fibroblast – a stellate or spindle-shaped motile cell with cytoplasmic processes present in connective tissue, capable of forming collagen fibers.
Fibroid – colloquial term for fibroma (a fibrous, encapsulated, connective-tissue tumor), especially a fibroma of the uterus.
Fibromyalgia – chronic pain in muscles and soft tissues surrounding joints.
Fibronectin – any one of a group of fibrous linking proteins present in blood plasma and extracellular matrix.
Fibrosis – abnormal formation of fibrous tissue.
Fimbria (fimbral) – any structure resembling fringe or border.
Fission, cell – in microbiology, a method of asexual reproduction in bacteria, protozoa, and other lower forms of life; in cell biology, the partition of one organelle into two, as for example the fissioning mitochondrion.
Fistula – in anatomy, an abnormal tubelike passage from a normal cavity or tube to a free surface or to another cavity; may be due to congenital incomplete closure of parts, or may result from abscesses, injuries, or inflammatory processes.
Fluorophore – peptide sequence that mediates fluorescence; fluorescent probes use a fluorophore are conjugated to antibodies or other molecules designed to localize within a specific region of a cell or to respond to a specific stimulus such as pH.
Flux (fluence) – generally, a rate of flow.
fMLP – N-formyl-methionyl-leucyl-phenylalanine, a known chemoattractant for granulocytes and macrophages.
Foreign body reaction – a variation in normal tissue behavior caused by the presence of a foreign material .
Frustrated phagocytosis – see Phagocytosis, frustrated.
Fullerene – a closed-cage molecule consisting of linked pentagons, hexagons, heptagons, or other polygonal elements; originally referred to carbon-only structures but may also represent the entire class of molecules having this geometry, regardless of atomic constituency (Section 2.3.2).
Functionalized – in chemistry, an otherwise chemically inert structure is functionalized when a chemically active ligand or moiety is covalently bonded to it.
Fundus, gastric – uppermost portion of the stomach, posterior and lateral to the entrance of the esophagus.
Fusion, cell – in cell biology, fusion is the merging of vesicles budded from the ER into the Golgi complex, or of endosomes with lysosomes, or of the contents of two cells by artificial means without the destruction of either, resulting in a heterokaryon that, for at least a few generations, will reproduce its kind (this was once an important method in assigning loci to chromosomes).
Fusogen (fusion protein) – specialized proteins that facilitate penetration of plasma membrane.
g – unit of gravitational acceleration (9.81 m/sec2); describes the mean gravitation force experienced by a mass at rest on Earth’s surface.
Galvanic – pertaining to electrical direct current, usually chemically generated.
Galvanotaxis, cellular – electric field-induced cell migration.
Ganglion – a mass of nervous tissue composed principally of nerve-cell bodies and lying outside the brain or spinal cord (e.g. the chains of ganglia that form the main sympathetic trunks, or the dorsal root ganglion of a spinal nerve).
Ganglioside – a particular class of glycosphingolipid present in nerve tissue and in the spleen.
Gastro- (gastric) – pertaining to the stomach.
Gastrointestinal – pertaining to the stomach and intestine.
Gaucher’s disease – a chronic congenital disease of lipid metabolism caused by a deficiency of the enzyme beta-glucocerebrosidase, wherein glycosphingolipids accumulate in the reticuloendothelial cells.
Gavage – feeding with a stomach tube or with a tube passed through the nares, pharynx, and esophagus into the stomach.
Genotoxicity – toxic to the genetic material in cells.
Gentamicin – an antibiotic derived from the fungi of the genus Micromonospora.
Giant cells (phagocytic) – a large cell with several nuclei, appearing to be made up of many cells (Section 188.8.131.52).
Gingiva (gingival) – the gum; the tissue that surrounds the necks of the teeth.
Glaucoma – a group of eye diseases characterized by increase in intraocular pressure, resulting in atrophy of the optic nerve and may produce blindness.
Glia cells – neuroglial cells including astrocytes, oligodendroglia and microglia.
Gliosis – proliferation of neuroglial tissue in the central nervous system.
Glomerulonephritis – a form of nephritis in which the lesions involve primarily the glomeruli.
Glomerulus, renal – one of the small structures in the malpighian body of the kidney made up of capillary blood vessels in a cluster and enveloped in a thin wall.
Glucan – polyglucose particles.
Glucosyl – a glycoprotein moiety.
Glycocalyx – a thin layer of glycoprotein and polysaccharide that covers the surface of some cells, such as muscle cells, fibroblasts, pericytes, and epithelial cells, and contributes to the basal lamina (Section 184.108.40.206).
Glycolipids – patterns of glucose residues attached to membrane lipids.
Glycoprotein – a protein molecule with carbohydrate moieties attached.
Glycosylation – the covalent bonding of carbohydrate moieties to another molecule.
Golgi complex/apparatus – in cell biology, individual stacks of membranes near the endoplasmic reticulum involved in glycosylating proteins and sorting them for transport to different intracellular locations (Section 220.127.116.11).
Goodpasture’s syndrome – progressive glomerulonephritis, hemoptysis, and hemosiderosis.
Gout – hereditary metabolic disease that is a form of acute arthritis and is marked by inflammation of the joints.
Graft – tissue that is transplanted or implanted in a part of the body to repair a defect.
Gram-negative – losing the stain and taking the color of the red counterstain in Gram’s method of staining.
Gram-positive – retaining the color of the gentian violet stain in Gram’s method of staining.
Granule – a small, grainlike body. Small granules may be found in cells, containing stores of nutrients; large granules may be formed in tissues following a granulomatous reaction.
Granulocyte – a granular leukocyte; a polymorphonuclear (nucleus composed of two or more lobes or parts) leukocyte, including basophils, eosinophils, and neutrophils.
Granuloma – a nodular inflammatory lesion, usually small or granular, that is firm, persistent, and contains compactly grouped mononuclear phagocytes. Actively growing provisional soft tissue that precedes remodeling phase of inflammatory response; may become chronic in the absence of resolution .
Granulomatous reaction – producing a granuloma, a granular tumor or growth, usually of lymphoid and epithelioid cells; an encapsulation reaction to the presence of a foreign object in the body that cannot be readily phagocytosed (Section 18.104.22.168).
Granulopoietic (granulomatogenesis) – producing granulocytes.
Graphene – monoatomic graphite sheet that forms the walls of fullerenes and carbon nanotubes.
Growth factors – biochemicals that promote division and proliferation of specific cell types.
GTP – guanosine triphosphate.
HA – see hydroxyapatite.
Hageman factor – clotting factor XII, a human plasma
Hallervorden-Spatz disease – progressive, degenerative disease, beginning in childhood, of the globus pallidus, red nucleus, and reticular part of the substantia nigra of the brain.
Hamaker constant – in surface science, a physical constant that describes the strength of van der Waals attractive forces between different materials as a function of the radius of curvature and separation distance between two surfaces (Section 9.2.1).
Haptic – operated by, or pertaining to, the sense of touch.
Haptotaxis – directed migration of cells along surfaces with gradients of immobilized factors.
Hct – see hematocrit.
Heat capacity – the ratio of the heat input to the temperature increase in a system.
Heat shock proteins (HSPs) – present in all normal living cells; act as “chaperones” to assist new or distorted proteins to properly fold, and help to shuttle proteins from one cellular compartment to another and to transport old proteins to intracellular “garbage disposal” sites; are also induced when a cell undergoes various types of environmental stresses like heat, cold or oxygen deprivation.
Heinz bodies – granules in red blood cells due to damage of the hemoglobin molecules.
HEMA – hydroxyethylmethacrylate (e.g., polymer).
Hemato- – pertaining to blood.
Hematocrit (Hct) – volume-fraction or bloodstream concentration of erythrocytes (red blood cells), expressed as a percentage.
Hematoma – a swelling or mass of blood (usually clotted), confined to an organ, tissue, or other space, caused by a break in a blood vessel.
Hematopoietic – pertaining to the production and development of blood cells.
Hemidesmosome – the half of a desmosome (structure binding adjacent epithelial cells) produced by epithelial cells for attachment of basal surface of the cell to the underlying basement membrane or the enamel or cementum tooth surface in the case of junctional epithelium.
Hemocompatibility – biocompatibility with the blood.
Hemodialysis – a method for providing the function of the kidneys by circulating blood through tubes made of semipermeable membranes.
Hemoglobinuria – presence of hemoglobin in the urine, but free from red blood cells.
Hemolysis (hemolytic) – fragmentation of red blood cells, liberating hemoglobin.
Hemolytic-uremic syndrome – an acute condition consisting of microangiopathic hemolytic anemia, thrombocytopenia, and acute nephropathy.
Hemoptysis – expectoration of blood arising from the oral cavity, larynx, trachea, bronchi, or lungs.
Hemorrhagic – pertaining to bleeding.
Hemosiderosis – condition characterized by deposition, especially in liver and spleen, of hemosiderin (an iron-containing pigment).
Hemostasis – arrest of bleeding.
Heparin – a polysaccharide that inhibits coagulation by preventing conversion of prothrombin to thrombin by forming an antithrombin.
Hepatic – pertaining to the liver.
Hepatocarcinogenic – tending to cause liver cancer.
Hepatocyte – the most common tissue cell found in the liver.
Hepatomegaly – abnormal enlargement of the liver.
Hernia – protrusion or projection of a part of an organ through the wall of the cavity that normally contains it.
Hilus (hilar) – depression or recess at entrance or exit of a duct into a gland, or of nerves and vessels into an organ.
Hippocampus (hippocampal) – the complex, internally convoluted structure that forms the medial margin of the cortical mantle of the cerebral hemisphere.
Histamine – a chemical substance, produced from the amino acid histidine, normally present in the body; exerts a pharmacological action when released from injured cells.
Histiocyte – a macrophage present in all loose connective tissues; part of the RES.
Histiocytosis – excessive multiplication of histiocytes, which appear in the blood in unusual numbers.
Histiocytoma – a tumor containing histiocytes.
Histology – the study of tissues.
Histonatation – in medical nanorobotics, locomotion (swimming) through tissues by a nanorobot (Section 9.4.4)
Histopenetration – in medical nanorobotics, penetration through dermis and internal tissue spaces by motile nanorobots.
HLA complex – Histocompatibility Locus Antigens, formerly known as Human Leukocyte Antigen (or Associated) complex.
Homeostasis – in physiology, a state of equilibrium of the internal environment of the body that is maintained by dynamic processes of feedback and regulation; homeostasis is a dynamic equilibrium (changing balance), keeping cells within the physical and chemical limits that can support life.
Homologous – similar in form (e.g. fundamental structure and origin), but not necessarily in function.
Homotypic – of the same form and type.
Hormone – a chemical substance that originates in an organ, gland, or part and is conveyed through the blood to another part of the body, stimulating that other part by chemical action to increase functional activity or to increase secretion of another hormone.
Host response – the local and systemic response, other than the intended therapeutic response, of living systems to the material ; the reaction of a living system to the presence of a material .
Host response, local – the response, other than the intended therapeutic response, of tissue and organs contacting a biomaterial .
Host response, remote – the response, other than the intended therapeutic response, of remote tissue and organs in an individual with one or more implants .
Host response, systemic – the distributed or disseminated response, response, other than the intended therapeutic response, of tissue and organs in an individual with one or more implants .
HSA – human serum albumin. See also albumin.
Humoral – pertaining to body fluids or substances contained in them.
Hyaline – material deposited in the glomerulus in certain forms of glomerulonephritis.
Hyaline bodies – homogeneous substance; the result of colloid degeneration, found in degenerated cells.
Hyaluronic acid – tissue cement or “ground substance” found in human connective tissue.
Hybrid artificial organ – see artificial organ, hybrid.
Hybridization – combination of different electron bonding orbitals to form four equivalent tetrahedral bond orbitals, esp. in carbon.
Hybridoma – the cell produced by the fusion of an antibody-produced cell and a multiple myeloma cell, capable of producing a continuous supply of identical antibodies.
Hydrocarbon – a molecule consisting only of H and C.
Hydrocephalus – the increased accumulation of cerebrospinal fluid within the ventricles of the brain.
Hydrodynamics – in physics, the study of the action of and motion of (and in) water and other liquids.
Hydrogen bond – the weak bond between a positively charged hydrogen atom that is covalently bound to one electronegative atom, and another electronegative atom.
Hydrolysis – a (hydrolytic) reaction in which a covalent bond is broken with the incorporation of a water molecule.
Hydrophilicity – tending to mix with water; wettable; nonpolar. Hydrophilic groups interact with water, so that hydrophilic regions of protein or the faces of a lipid bilayer reside in an aqueous environment. Compare hydrophobicity.
Hydrophobic force – water molecules are linked by a network of hydrogen bonds; a nonpolar nonwetting surface such as wax cannot form hydrogen bonds, hence repels water.
Hydrophobicity – tending not to mix with water; nonwetting; polar. Hydrophobic groups repel water, so that they interact with one another to generate a nonaqueous environment. Compare hydrophilicity.
Hydrostatic – pertaining to the pressure of fluids or to fluid properties when in equilibrium.
Hydroxyapatite – the apatite form of calcium phosphate present with calcium carbonate in the bones and skeleton.
Hydroxyl – an OH- group or ion.
Hyperalgesia – excessive sensitivity to pain.
Hyperbaric – exposure to, or having pressure greater than, normal atmospheric pressure.
Hypercapnia – increased amount of carbon dioxide in the blood.
Hyperhidrosis – abnormally excessive sweating.
Hyperopia – farsightedness.
Hyperplastic (hyperplasia) – excessive proliferation of normal cells in the normal tissue arrangement of an organ.
Hypersensitivity reactions – the reaction of the body to antigens.
Hypertension – abnormally high blood pressure.
Hyperthermia – unusually high fever.
Hypertrophy – increase in size of an organ or structure that does not involve tumor formation.
Hyperventilation – increased lung ventilation leading to abnormally low carbon dioxide in blood.
Hypervolemic – abnormal increase in the volume of circulating blood.
Hypha – a filament of mold, or part of a mold mycelium (mass of filaments constituting the vegetative body of fungi).
Hypocapnia – decreased amount of carbon dioxide in the blood.
Hypokalemia – extreme potassium depletion in the circulating blood.
Hyponatremia – extreme sodium depletion in the circulating blood.
Hypotension – low blood pressure.
Hypothalamus – part of the brain lying below the thalamus.
Hypothermia – having a body temperature below normal.
Hypothyroid – marked by insufficiency of thyroid secretion.
Hypotonic – see isotonic.
Hypotonia – reduced tension; relaxation of arteries; loss of tonicity of the muscles or intraocular pressure.
Hypovolemic – diminished blood volume.
Hypoxia – a condition in which the tissues are not receiving enough oxygen to sustain their metabolic activity.
Hysteresis – failure of related phenomena to keep pace with each other.
IAP – inhibitor of apoptosis.
Iatrogenic disorder – an adverse condition induced in a patient by the actions of a physician.
ICD patch – implantable cardioverter defibrillator (e.g., with epicardial patch electrodes).
Idiopathic – pertaining to conditions without clear pathogenesis.
Idiotype – in immunology, the specific region of the antibody-binding (Fab) region of the immunoglobulin molecule to which the specific antigen binds.
Ig – immunoglobulin (IgG, IgA, IgM, IgD, IgE); see antibody.
IJE – peri-implant junctional epithelium.
Ileum (ileal) – lower three-fifths of the small intestines from the jejunum to the ileocecal valve.
Immune response – host response involving either humoral or cellular specific immune mechanisms .
Immunofixation – a laboratory technique used to identify proteins in which immunoglobulins (which appear as a “gamma” band in protein electrophoresis) are separated, allowing the individual immunoglobulins to be identified; immunofixation electrophoresis consists of an electrophoretic phase followed by a fixation phase in which antiserum is used to precipitate the protein, thus enhancing the results of standard protein electrophoresis, giving more rapid results and greater sensitivity.
Immunogen – an agent that can induce an immune response; all immunogens are antigens.
Immunoglobulins – a class of glycoproteins; see antibody.
Immunoradiometric assay – an assay based on the reversible and non-covalent binding of an antigen by a specific antibody labeled with a radioactive nuclide as a tracer.
Immunosuppression – prevention of formation of an immune response.
Immunotoxin – toxic agent attached to an antibody molecule, used to specially target tumor cells.
Impedance – opposition to flow (e.g. fluid, electrical, etc.) when flow is steady, or the driving pressure per unit flow when flow is changing; the resistance of an acoustic system to being set in motion.
Impermeant – incapable of permeating.
Implant – a device placed within an animal or human body by the act of implantation ; a medical device made from one or more biomaterials that is intentionally placed within the body, either totally or partially buried beneath an epithelial surface .
Implantation – placement of a device or material within the body of an animal or human by a medical or surgical professional, in such a way as to breach one or more epithelial layers, and to leave materials or components in place after the initial procedure is completed .
Incapsulation – resolution of inflammation, in which the implant is surrounded and walled off from normal tissue by a collagenous, relatively acellular tissue called a capsule, which resembles scar tissue; in a bony location, the capsule may be mineralized and is called a sequestrum .
Incontinence – inability to retain urine, semen, or feces, through loss of sphincter control or because of cerebral or spinal lesions.
In cyto – within a biological cell.
India ink – a black ink consisting of an aqueous suspension of natural black pigment usually made from bone black, lampblack, or amorphous carbon from combustion (soot); aka. China ink.
Inert biomaterials – see biomaterials, inert
Infarct – an area of tissue in an organ or part that undergoes necrosis following cessation of blood supply.
Inferior – beneath or lower; often refers to the undersurface of an organ or indicates a structure below another structure.
Inflammatory response – the cell-mediated local and regional response directed toward stabilizing injured tissue, restoring physiological status quo ante, removing dead or damaged tissue elements and foreign material, and correcting structural and functional loss due to the initial insult (Section 15.2.4). The four classical signs of inflammation are redness (rubor), swelling (tumor), pain (dolor), and heat (calor) .
Infraorbital – beneath the orbit (the cavity in the skull containing the eyeball).
Infrarenal – below the kidney.
Ingrowth – formation of tissue within pores, etc. in the body of an implant .
In sanguo – within the bloodstream.
Insufflation – the act of blowing a gas, vapor, or powder into a cavity, such as the lungs.
Integral membrane protein – in cell biology, an amphipathic protein embedded in the lipid bilayer of the cell which cannot be extracted from the membrane without disrupting the lipid bilayer; most integral proteins are transmembrane proteins.
Integration – resolution of inflammation, in which the implant becomes well-integrated with the adjacent biological tissues; occurs for a very limited number of materials, such as bioactive glasses of selected compositions and some metals such as pure titanium for which direct bonding or apparent adhesion to normal tissue may take place .
Integrins – cell surface adhesion receptors (~200 kilodalton) that mediate cellular connection to the extracellular matrix and are expressed on a wide variety of cells. Most cells express several integrins; most integrins are involved in attachments to the cytoskeletal substratum.
Integument – the skin, consisting of the dermis and epidermis; a covering.
Interactive biomaterials – see biomaterials, interactive.
Intercalated – inserted between two others, as something interposed.
Intercostal – between the ribs.
Intermediate filament – the most stable of the cytoskeletal elements; high tensile strength and comparative positional stability; serve as internal guy wires to resist mechanical stress on the cell, providing a scaffold supporting the entire cytoskeletal framework (Section 22.214.171.124(C)).
Interstitial (interstitium) – pertaining to extracellular interstices or spaces within an organ or tissue.
Intima – innermost coat of a structure, e.g., a blood vessel.
Intraarterial – within the artery(ies).
Intraarticular(-ate) – within a joint.
Intracellular – inside the cell.
Intracranial – within the cranium or skull.
Intraepithelial – residing in the epithelium.
Intrahepatic – inside the liver.
Intraluminal – within any tubular structure.
Intramuscular – inside muscle tissue.
Intranigral – inside a specific region in the brain.
Intranuclear – inside the cell nucleus.
Intraocular – within the eyeball.
Intraoperative – occurring during surgery.
Intraperitoneal (IP) – within the peritoneal (abdominal) cavity.
Intrarenal – inside the kidney.
Intratracheal – introduced into, or inside, the trachea.
Intravasation – reverse diapedesis.
Intravascular – inside a blood vessel.
Intravenous – inserted into a vein.
Intravitreous (intravitreal) – inside the vitreous humor of the eye.
Intrusiveness, volumetric – in medical nanorobotics, a measure of the degree to which artificial nanosystems can safely and harmlessly volumetrically displace natural biological systems.
Intussusception – the slipping of one part of an intestine into another part just below it; invagination.
In vacuo – in a vacuum (viz. the ablative case of the 2nd-declension Latin adjective “vacuus”).
Invaginate – to place or receive into a sheath; to receive within itself or into another part.
In vitro – in glass, as in a test tube; performed in the laboratory, usually involving isolate tissue, organ, or cell preparations.
In vivo – inside the living human body; performed on a living organism.
Irido- – pertaining to the iris of the eye.
Ischemia – local and temporary deficiency of blood supply due to obstruction of the circulation into a body part.
ISFET – Ion Sensitive Field Effect Transistor.
Isoelectric – having equal electric potentials; neither positively nor negatively charged.
Isoforms – any one of multiple forms of a functional protein that differ in amino acid sequence and electrophoretic mobility.
Isomer – one of two more chemical substances that have the same molecular formula but different chemical and physical properties due to a different arrangement of the atoms in the molecule; for example, dextrose is an isomer of levulose. Isomers may be geometric, optical, or structural.
Isothermal – held, or existing, at a constant temperature.
Isotonic – animal cells containing a solution which exerts an osmotic pressure approximately equal to that of the surrounding fluid are isotonic or isoosmotic to that fluid. Stronger solutions that cause cells to shrink are hypertonic; weaker solutions that cause cells to swell are hypotonic.
Isotope – any of two or more forms of the same chemical element that have nearly identical chemical properties but which differ in the number of neutrons contained in each atomic nucleus; many isotopes are radioactive.
Isotropic – the same in all directions.
Isotypes – in immunology, the determinants on the Ig molecule that distinguish among the main classes of antibodies of a given species (the same for all normal individuals of that species).
IP – see intraperitoneal.
IV – see intravenous.
Jejunum (jejunal) – the second portion of the small intestine extending from the duodenum to the ileum.
Kallikrein – an enzyme normally present in blood plasma, urine, and body tissue; is one of the most potent vasodilators when activated (to form kinin).
Kaolin – a yellow-white or gray clay powder formed of hydrated aluminum silicate.
Karyogamy – union of nuclei in cell conjugation.
Keloids – scar formation in the skin following trauma or surgical incision.
Keratin – a sulfur-rich scleroprotein or albuminoid present largely in cuticular (pertaining to cuticles) structures.
Keratinocyte – a cell of the epidermis, and parts of the mouth, that produces keratin.
Keratitis – inflammation of the cornea, with pain; usually associated with decreased visual acuity.
Keratocyte – corneal fibroblasts.
Keratomileusis – plastic surgery of the cornea in which a portion is removed, its curvature reshaped, and then is reattached; can also be done in situ with laser.
KHz – kilohertz; thousands of cycles per second.
Kinetochore – a large protein complex that forms at the surface of the centromere of chromosomes and controls separation of the chromosomes to daughter cells by mediating microtubule association with chromosomes.
Kininogen – substance that produces a kinin when acted upon by certain enzymes.
Kinins – a group of polypeptides with considerable biological activity, e.g., influencing smooth muscle contraction, inducing hypotension, inciting pain, and increasing blood flow and permeability of blood capillaries.
Kirschner wire – steel wire placed through a long bone, to apply traction to the bone.
Knowles pin – a mechanical prosthesis for bone fracture fixation used in place of plates or Kirschner wires, e.g., for acute adult mid-clavicular fractures.
Kupffer cells – macrophages lining the sinusoids of the liver (Section 8.2.5).
Labile – not fixed, unsteady, easily disarranged; easily altered or decomposed by heat or chemicals.
Laceration (lacerative) – a wound or irregular tear of the flesh.
Lacrimal – pertaining to the tears (eye fluid).
Lactoferrin – an enzyme released in phagocytosis by neutrophils and macrophages that combines with iron in the blood.
Lamellipodia – variable extensions of the cell membrane; a cytoplasmic veil produced on all sides of a migrating polymorphonuclear leukocyte (granulocyte).
Lamina – a thin flat layer or membrane.
Lamina propria – thin layer of fibrous connective tissue lying immediately beneath the surface epithelium of mucous membranes.
Laminar (Poiseuille) flow – fluid flow that moves exclusively along separate and independent parallel flow planes (i.e. streamlines), generally with an axisymmetric parabolic profile if in a tube. Laminar flow minimizes the impedance (resistance) and energy dissipation of fluid flow.
Laminin – a large glycoprotein component of ECM that binds to specific integrin molecules on tissue cell surface, with a primarily adhesive function.
Langerhans cells – dendritic cells in human skin.
Langmuir (-Blodgett) film – thin film created by successive adhesion of a series of molecular monolayers to a surface, allowing both thickness and composition in the vertical axis to be adjusted to 0.1-nm by controlling the structure of the molecules comprising each individual monolayer during deposition.
Larynx (laryngeal) – the enlarged upper end of the trachea below the root of the tongue; the organ of voice.
Lavage – washing out of a cavity.
LD50 – a dose of or exposure to a toxic influence that produces death in 50% of organisms exposed to it.
Leachate – water that has passed through a material and in doing so has accumulated dissolved substances (the leachates).
Leukapheresis – see apheresis.
Leukergy – anergy of leukocytes.
Leukocytes (white blood cells) – the primary effector cells that respond to infection and tissue damage in the human body. There are two types: granulocytes (including basophils, eosinophils, and neutrophils) and agranulocytes (including monocytes and lymphocytes). Leukocytes are formed from two stem cell populations in the bone marrow. The myeloid stem cell line produces granulocytes and monocytes, while the lymphoid stem cell line produces lymphocytes. Lymphoid cells travel to the thymus, spleen and lymph nodes, where they mature and differentiate into active, antigen-specific lymphocytes.
Leukocytolysis – fragmentation of white blood cells.
Leukocytosis – abnormal increase in number of leukocytes in the blood, usually transient, generally caused by presence of infection.
Leukocyturia – leukocytes in the urine.
Leukoembolization – vascular trapping of white cells, forming a blocking embolus.
Level of host (or material) response – the nature of the host (or material) response in a standard test with respect to the response obtained with a reference material .
Lewy bodies – neuronal cells with pigmented inclusion bodies; found in Parkinson’s disease.
Ligament – a band or sheet of strong fibrous connective tissue connecting the articular ends of bones, binding them together and facilitating or limiting motion.
Ligation, molecular – the formation of a phosphodiester bond to link two adjacent bases separated by a nick in one strand of a double helix of DNA; the term can also be applied to blunt-end ligation and to the joining of RNA.
Lipase – a lipolytic or fat-splitting enzyme found in the blood, pancreatic secretion, or tissues.
Lipid bilayer – in cell biology, the form taken by a concentration of lipids in which the hydrophobic fatty acids occupy the interior and the hydrophilic polar heads face the exterior; primary constituent of the plasma membranes of cells.
Lipids – molecules having hydrophilic polar heads, containing phosphate (phospholipid), sterol (such as cholesterol), or saccharide (glycolipid) connected to a hydrophobic tail consisting of fatty acid.
Lipofuscin – brown pigment granules representing lipid-containing nondegradable residues of lysosomal digestion (Section 126.96.36.199).
Lipofuscinosis – abnormal deposition of lipofuscin in tissues.
Lipoma – a fatty tumor.
Lipophilic – having an affinity for lipids (fats); nonpolar.
Lipophobic – repulsed by lipids (fats).
Lipoproteins – conjugated proteins consisting of simple proteins combined with lipid components.
Liposomes – closed spherical bilayers formed by lipid molecules with varying radii from 10 nm to micrometers. See also micelles.
Lissencephaly – condition in which the brain is smooth owing to failure of development of cerebral gyri.
Listeriosis – disease affecting humans and many animals, caused by Listeria monocytogenes (a soil saprophyte); most common manifestation is meningitis.
Lithophagy – swallowing stones, sand, or other mineral matter.
Lithotripsy – crushing of a stone in the bladder or urethra.
Load error – in control theory, minimum range of variation in a control variable that is necessary to provoke a response from a control system.
LPS – lipopolysaccharide, the lipid used to construct the outer leaflet of the outer bilayer membrane of Gram-negative bacteria.
LTIC – low temperature isotropic carbon (Section 188.8.131.52).
Lumbar – pertaining to the loins (the part of the back between thorax and pelvis).
Lumen – the interior, especially of a compartment bounded by membranes, as for instance the endoplasmic reticulum or the mitochondrion.
Luminal – pertaining to the interior of a cavity, tube, or vessel.
LVAD – left ventricular assist device.
Lymph – an alkaline fluid found in the lymphatic system (Section 184.108.40.206).
Lymphadenopathy – swelling and morbid change in lymph nodes.
Lymphangitis – inflammation of lymph vessels.
Lymphatic system – includes all structures involved in the conveyance of lymph from the tissues to the bloodstream, including lymph capillaries, lacteals, lymph nodes, lymph vessels, main lymph ducts, and cisterna chyli (Section 220.127.116.11).
Lymphedema – edema due to obstruction of lymph vessels.
Lymphocompatible – biocompatible with important components of the lymphatic system, especially lymphocytes.
Lymphocyte – a morphologically distinct variety of leukocytes, comprising 20-44% of all white blood cells. But only ~2% of all lymphocytes present in the human body are in the bloodstream; most reside elsewhere, particularly in the lymph and the lymph nodes. B-lymphocytes differentiate into antibody-secreting plasma cells, whereas T-lymphocytes play diverse regulatory roles in the immune response.
Lymphocytopenia – less than normal number of lymphocytes in the blood.
Lymphokines – a cytokine secreted by a lymphocyte.
Lymphotrophic – tending to accumulate in lymph nodes.
Lysis (lytic) – in microbiology, the death of a bacterium at the end of a bacteriophage infective cycle when the bacterium bursts open to release the progeny of an infecting phage; also applies to eukaryotic cells, as for example infected cells that are attacked by the immune system. More generally, dissolution or decomposition.
Lysosomes – small bodies inside cells, enclosed by membranes, that contain hydrolytic enzymes that are part of the cell’s digestive apparatus (Section 18.104.22.168).
Lysozyme (muramidase) – an enzyme that is destructive to cell walls of certain bacteria, found in white blood cells of the granulocytic and monocytic series.
MAb – see monoclonal antibody.
MAC – membrane attack complex (complement system; Section 22.214.171.124).
Machine-phase nanotechnology – molecular nanotechnology-based mechanical devices.
Macromolecule – a molecule of colloidal size, typically 1-100 nm in diameter or length, consisting most notably of proteins, nucleic acids, and polysaccharides.
Macrophage – a monocyte that has left the circulation and settled and matured in a tissue; found in large numbers in the spleen, lymph nodes, alveoli, and tonsils, with ~50% found in the liver as Kupffer cells. Along with neutrophils, macrophages are the major phagocytic cells of the immune system, able to recognize (and then ingest) foreign antigens via chemical receptors on the surface of their cell membranes. Macrophages also serve a vital role by processing antigens and presenting them to T-cells, activating the specific immune response.
Macroscopic – easily visible to the human naked eye; typically ~1 mm3 or larger.
Macula densa cells – closely packed cells in the distal tubular epithelium of each nephron in kidney; may function as chemoreceptors.
Macule (macular) – discolored spot or patch on the skin, neither elevated nor depressed, of various colors, sizes, and shapes.
Macular degeneration – degeneration of the macular area of the retina of the eye.
Maillard reaction – in food science, the "browning" reaction that occurs between proteins and reducing sugars as they are heated.
Major histocompatibility complex (MHC) – the complex of HLA genes on the short arm of human chromosome 6 (Section 126.96.36.199).
Malignant – growing worse, resisting treatment, threatening to produce death; said of cancerous growths.
Malpighian capsule – a spherical body found in cortex of kidney consisting of a glomerulus and Bowman’s capsule.
Mandible (mandibular) – horseshoe-shaped bone forming the lower jaw.
Mannose – a polysaccharide (an aldohexose) present in certain plants.
March hemoglobinuria – impact hemolysis.
Margination – adhesion of leukocytes to endothelial cells lining the walls of a blood vessel, during the relatively early stages of inflammation; more generally, the process of differential radial migration among suspended particles of different sizes during fluid flow through a tube.
Marsupialization – see extrusion (implants).
Martensitic – a highly twinned lower temperature structure with a stress-strain curve having a plateau phase more like that of an elastomer than a metal; compare austenitic.
Mast cells – cells resident in connective tissue just below epithelial surfaces, serous cavities, and around blood vessels, that synthesize, store, and release (upon stimulation) histamine and other local chemical mediators of inflammation (e.g. leukotrienes).
Material response – the response of the material to living systems .
Matricellular proteins – extracellular matrix proteins.
Maxillary – pertaining to the upper jaw.
Maxillofacial – pertaining to the maxilla and face.
Meatus – a passage or opening.
Mechanocompatibility – the mechanical biocompatibility of nanodevices or nanorobotic systems as they interact with the organs, tissues and cells of the human body (Chapter 15.5).
Mechanoenzyme – enzyme producing mechanical actuation when activated.
Mechanoreceptor – a receptor that receives mechanical stimuli such as pressure from sound or touch.
Mechanosensitivity – see mechanoreceptor.
Mechanosynthesis – chemical synthesis controlled by mechanical systems operating with atomic-scale precision, enabling direct positional selection of reaction sites; synthetic applications of mechanochemistry.
Media – middle or muscular coat of an artery.
Mediastinum (mediastinal) – the mass of organs and tissues separating the lungs; containing the heart and its large vessels, trachea, esophagus, thymus, lymph nodes, and connective tissue.
Medical device – see device, medical.
Medulla (medullary) – the inner or central portion of an organ; compare cortex.
Medulla oblongata – enlarged portion of the spinal cord in the cranium, after the cord enters the foramen magnum of the occipital bone; the lower portion of the brain stem.
Megakaryocytes – a large bone marrow cell with multiple nuclei.
Melanosome – the pigment granule produced by melanocytes.
Melittin – a small protein containing 26 amino acid
residues that is the principal toxic component of honeybee venom.
Membrane – in cell biology, an asymmetrical lipid bilayer that has lateral fluidity and contains proteins; in anatomy, a thin, soft, pliable layer of tissue that lines a tube or cavity, covers an organ or structure, or separates one part from another (Section 188.8.131.52).
Membrane proteins – in cell biology, plasma membrane proteins that have hydrophobic regions that allow part or all of the protein structure to reside within the membrane; the bonds involved in this association are usually noncovalent (Section 184.108.40.206).
Membranolytic – causing the physical failure of a membrane.
Meningeal cells – cells of the meninges (the three membranes investing the spinal cord and brain).
Mesangium (mesangial) – the suspensory structure of the renal glomerulus.
Mesentery (mesenteric) – a peritoneal fold encircling the greater part of the small intestines and connecting the intestine to the posterior abdominal wall.
Mesothelioma – a rare malignant tumor of the mesothelium (the epithelium covering the serous membranes) of the pleura, pericardium, or peritoneum.
Messenger RNA (mRNA) – the RNA whose sequence corresponds to that of exons in the transcribed gene, which embodies the codons and is translated into the protein gene product.
Metabolite – any product of metabolism.
Metamorphic – in medical nanorobotics, capable of adopting multiple physical configurations via smooth changes from one configuration to another (Section 5.3).
Metastasize (metastasis) – usually refers to the manifestation of a malignancy (e.g. of cancerous body cells) as a secondary growth arising from the primary growth, but in a new location.
Metazoa – all multicellular life. Compare protozoa.
MHC – see major histocompatibility complex.
MHz – megahertz; millions of cycles per second.
Micelle – a self-assembling hollow spheroidal aggregate of amphipathic lipids in a polar liquid (e.g. aqueous) medium. See also liposomes.
Microangiopathy – pathology of small blood vessels.
Microautophagocytosis – digestion within a cell of portions of individual cell organelles or mitochondria that have been injured or have atrophied.
Microbivore – in medical nanorobotics, an artificial mechanical phagocytes  (Chapter 23).
Microdomains, cellular – see microzones.
Microglia – resident macrophages in brain tissue, spinal cord, and retina.
Microgravity – conditions of below-normal gravity, e.g. in Earth orbit; hypogravity.
Micron – one-millionth of a meter; a micrometer.
Microplicae – microscopic folds.
Microsomes (liver) – membrane fractions derived from human or animal tissues or cells grown in culture; most membrane-bound enzymes are associated with microsomes.
Microtubules – filaments consisting of dimers of tubulin; interphase microtubules are reorganized into spindle fibers during mitosis (cell division), when they are responsible for chromosome movement.
Microvilli – microscopic projections from the free surface of cell membranes, greatly increasing the exposed surface area of the cell.
Microzones – physiologically persistent, localized, and essential intracellular chemical gradients, establishing intracellular compartmentation of metabolites without enclosure by membranes.
Micturition – urination.
Miliaria – vesicles caused by obstruction of sweat gland ducts.
Mimetic – imitative.
Miscible – capable of being mixed.
Mitochondrion – a self-reproducing organelle that provides energy for eukaryotic cells via oxidative phosphorylation (Section 220.127.116.11).
Mitogen – a protein substance derived from plants that is used in the laboratory to stimulate cells to divide.
Mitosis (mitotic) – in cell biology, the division of a eukaryotic somatic cell. The four (or five) sequential stages are prophase, (prometaphase), metaphase, anaphase, and telophase; the absence of mitosis is the interphase.
MNP – mononuclear phagocyte; see monocyte, macrophage, or lymphocyte.
MNT – see molecular nanotechnology.
Moiety – a portion of a molecular structure having some property of interest.
Molarity (M) – in chemistry, moles of solute per liter of solvent.
Mole – a number of instances of something (e.g. molecular objects) equal to ~6.023 x 1023 objects.
Molecular assembler – a general-purpose device for molecular manufacturing, able to guide chemical reactions by positioning individual molecules to atomic accuracy (e.g. mechanosynthesis) and to construct a wide range of useful and stable molecular structures according to precise specifications [8-10, 35]; Section 2.4.2.
Molecular machine – a mechanical device that performs a useful function using components of nanometer scale and a well-defined molecular structure; may include both artificial nanomachines and naturally occurring devices found in biological systems.
Molecular machine system – a system of molecular machines.
Molecular manufacturing – manufacturing using molecular machinery, giving molecule-by-molecule control of products via positional chemical synthesis, to produce complex molecular structures manufactured to precise specifications (Chapter 2; ).
Molecular nanotechnology – thorough, inexpensive control of the structure of matter based on molecule-by-molecule control of products and byproducts; the products and processes of molecular manufacturing, including molecular machinery; a technology based on the ability to build structures to complex, atomic specifications by mechanosynthesis or other means; most broadly, the engineering of all complex mechanical systems constructed from the molecular level.
Molecular sorting rotor – a class of nanomechanical device capable of selectively binding (or releasing) molecules from (or to) solution, and of transporting these bound molecules against significant concentration gradients (Section 3.4.2).
Monoclinic (crystal) – pertaining to crystals in which the vertical axis is inclined to one lateral axis but at right angles to the other.
Monoclonal antibody – antibodies derived from hybridoma cells; antibodies of exceptional purity and specificity.
Monocyte – a mononuclear phagocytic white blood cell derived from the myeloid stem cells, that is short-lived (~1 day half-life) and circulates in the bloodstream from which it moves into tissues, at which point it matures into a macrophage (which is long-lived). Monocytes represent 3%-8% of all white blood cells.
Monokine – chemical mediator released by monocytes and macrophages during the immune response; affects growth and activity of other WBCs.
Monomer – any molecule that can be bound to similar molecules to form a polymer.
Mononucleosis – presence of an abnormally high number of mononuclear leukocytes in the blood.
Monosaccharide – a simple sugar that cannot be decomposed by hydrolysis (e.g., fructose, galactose, glucose).
Morphogen – a (biochemical) factor that induces development of particular cell types in a manner that depends on its concentration.
Motile – capable of voluntary movement. Opposite of sessile.
MPS – mononuclear phagocyte system; see reticuloendothelial system (RES).
MRI – magnetic resonance imaging.
mRNA – see messenger RNA.
MSAD-C60 – chemical abbreviation for p,p’-bis(2-aminoethyl)-diphenyl-bis(monosuccinimide)-C60. 
MSDS – Material Safety Data Sheet (OSHA).
MSU – monosodium urate.
MSUM – monosodium urate monohydrate.
Mucoadhesivity – ability to adhere to mucous membranes.
Mucociliary escalator – a cilia-driven mucus flow from alveoli to trachea, carrying mucus-trapped micron-size particles toward the esophagus where this mucus can be swallowed, thus eliminating the trapped (inhaled) particles from the body.
Mucopolysaccharide – polysaccharides containing hexosamine and sometimes proteins that form chemical bonds with water, making a thick gelatinous substance found in many places in the body.
Mucosa – a mucous membrane; the moist tissue layer that lines a hollow organ or body cavity.
Mucosacompatibility – biocompatibility with mucosal tissues.
Mural – pertaining to a wall of an organ or part.
Murine – related to or derived from mouse.
Muscarine(ic) – a toxin with neurologic effects, isolated from mushrooms; an agent that stimulates the postganglionic parasympathetic receptor.
Muscular dystrophy – wasting away and atrophy of muscles.
Mutagenesis – induction of a permanent (inheritable) genetic change .
Mycotoxins – substances (produced by mold growing in food) causing illness or death when ingested by man or animals.
Myelin (myelinated) – a fatlike substance forming a sheath around the axons of certain nerves; composed of lipids and protein.
Myeloblast – immature bone marrow cell that develops into myelocyte, later maturing to a promyelocyte and eventually the granular leukocyte.
Myeloproliferative – concerning proliferation of bone marrow either in the bone marrow or extramedullary.
Myoblast – an embryonic cell that develops into muscle fiber cell.
Myocardial infarction – condition caused by partial or complete occlusion of one or more of the coronary arteries.
Myocardium – heart muscle.
Myocyte – a muscular tissue cell.
Myoma – a tumor containing muscle tissue.
Myopia – nearsightedness.
Myosin – a protein consisting of long chains of polypeptides joined to each other by side chains, present in muscle fibrils and constituting two-thirds of total muscle protein.
NADH – reduced form of NAD (nicotinamide adenine dinucleotide).
Nanoaggregate – in medical nanorobotics, a cluster of mutually attached nanodevices.
Nanocannula – in medical nanorobotics, a nanorobotic cannulation device.
Nanocrit (Nct) – in medical nanorobotics, volume-fraction in body fluid or bloodstream concentration of medical nanorobots, expressed as a percentage.
Nanoid shock – in medical nanorobotics, nanorobot-induced shock (Section 18.104.22.168); shock induced by nanorobots bearing endotoxin-homologous chemical moieties on their exterior surfaces, or releasing such moieties free into the serum.
Nanomachine – functional machine systems on the scale of nanometers; an artificial mechanical device constructed with precise molecular order using nanometer-scale components; any molecular structure large and complex enough to function as a machine.
Nanomanipulator – a nanorobotic manipulator device.
Nanomechanical – pertaining to the mechanical characteristics of nanomachines.
Nanomedicine – (1) the comprehensive monitoring, control, construction, repair, defense, and improvement of all human biological systems, working from the molecular level, using engineered nanodevices and nanostructures; (2) the science and technology of diagnosing, treating, and preventing disease and traumatic injury, of relieving pain, and of preserving and improving human health, using molecular tools and molecular knowledge of the human body; (3) the employment of molecular machine systems to address medical problems, using molecular knowledge to maintain and improve human health at the molecular scale.
Nanometer – a billionth of a meter, roughly the diameter of 3-7 atoms.
Nanoorgans – organs comprised of nanocomponents; nanorobotic organs.
Nanophase – having nanoscale features or components.
Nanopyrexia – in medical nanorobotics, condition of abnormally high temperature induced by nanorobotic devices or activities (Section 15.2.7).
Nanorobotics – the study of nanorobots, micron-scale robotic devices constructed out of nanoscale components.
Nanosecretagoguery – triggered enzyme release by nanorobots or free nanoparts.
Nanosystem – a set of nanoscale components, characterized by precise molecular order, working together to serve a set of purposes; complex nanosystems can be of macroscopic size.
Nanotechnology – engineering and manufacturing at nanometer scales; any technology related to features of nanometer scale, including thin films, fine particles, chemical synthesis, advanced microlithography, and so forth, as well as complex mechanical systems constructed from the molecular level.
Nanotubes – hollow fullerene tubes, including but not limited to single- and multi-walled carbon nanotubes, with submicroscopic, often nanoscale, diameters and a wide range of continuous lengths.
Nasopharynx – in anatomy, the nasal passages, mouth, and upper throat.
Nauseogenic – eliciting nausea (Section 22.214.171.124).
Navicyte – in medical nanorobotics, a mobile, mass-storage (nanorobotic) device, similar to a communicyte, that may be used to establish a navigational network inside the human body (Section 8.3.3).
Nct – see nanocrit.
Necrosis (necrotic) – the death of areas of tissue or bone, surrounded by healthy parts.
Necrotaxis – cell movement toward necrotic cells or tissue.
Neointima – a new intimal layer.
Neoplastic – pertaining to, or of the nature of, new and abnormal tissue (i.e. neoplasm) formation and growth.
Nephritis – inflammation of the kidney.
Nephro- – pertaining to the kidney.
Nephrolithiasis – presence of calculi in the kidney.
Nephropathy – disease of the kidney.
Neural crest cells – a band of cells extending longitudinally along the neural tube of an embryo from which cells forming cranial, spinal, and autonomic ganglia arise.
Neuralgia – severe sharp pain along the course of a nerve.
Neurite – the axial cylinder process of a neuron; both axons and dendrites are neurites.
Neuroglial cells – the tissue that forms the interstitial or supporting elements (cells and fibers) of the nervous system.
Neuron – a nerve cell, the principal structural and functional unit of the nervous system.
Neuronal ceroid-lipofuscinosis (NCL) diseases – recessively inherited neurodegenerative disease involving a lysosomal storage defect of cerebral lipofuscins, caused by the selected death of cortical neurons and retinal degeneration; aka. Batten disease.
Neuropeptide – any of a variety of neurotransmitter peptides found in neural tissue (e.g. endorphins, enkephalins).
Neuropil – network of unmyelinated fibrils into which nerve processes of CNS divide.
Neutropenia – abnormally small number of neutrophils in the blood.
Neutrophil – the most common type of granulocytic white blood cell. Neutrophils are responsible for much of the body’s protection against infection. Comprising ~60% of all white blood cells, neutrophils play the primary role in inflammation, easily recognizing foreign antigens and destroying them through phagocytosis. Neutrophils also may overreact to stimuli and become involved in tissue destruction, as in rheumatoid arthritis, myocardial reperfusion injury, respiratory distress syndrome, and ulcerative colitis.
NFPA – National Fire Protection Association.
Nidus – a focus of infection; a cluster or nestlike structure.
Niemann-Pick disease – hereditary disease; disturbance of sphingolipid metabolism characterized by hepatosplenomegaly, anemia, lymphadenopathy, and progressive mental and physical deterioration.
Nitrosylation – the covalent bonding of nitrogen-containing moieties to another molecule.
NK cells – natural killer cells (Section 126.96.36.199.1).
NO – nitric oxide.
Nociceptor – pain receptor (Section 188.8.131.52).
Nonthrombogenic (thromboresistant) – the characteristic of a material that leads to minimal thrombogenicity .
Nuclease – any enzyme that facilitates hydrolysis of nuclein and nucleic acids.
Nucleation – growth of droplets, films, or calculi due to the presence of a small seed particle which facilitates coalescence of these materials.
Occlusion – the closure, or state of being closed, of a passage.
Oleophilic – in chemistry, having a strong affinity for oils rather than water; lipotropic; see also lipophilic.
Oligosaccharide – a compound made up of a small number of monosaccharide units.
Ongrowth – formation of tissue directly on the surface of an implant; does not imply adhesion .
Oocyte – the early or primitive ovum (the female reproductive cell).
Oppenheimer effect – increased neoplasm incidence rates observed in rodents that are implanted with agents (not previously thought to be carcinogenic) in solid form rather than injected or fed in soluble or dispersed form; aka. foreign body carcinogenesis or solid-state carcinogenesis.
Opsonins – biochemical substances that coat foreign antigens, making those antigens more susceptible to recognition by macrophages and other leukocytes and thus increasing phagocytosis of the organism or object displaying those foreign antigens. The two main opsonins in human blood are complement and antibodies.
Opsonization – the coating action of opsonins, thus facilitating phagocytosis. Coating of bacteria or biomaterial surfaces with native proteins, such as complement factors, rendering them detectable as “foreign” by phagocytic cells .
OR – operating room.
Orbital cavity – bony pyramid-shaped cavity of the skull that contains and protects the eyeball.
Organelle – most commonly described subcellular compartment, located in the cytoplasm, that is surrounded by a membrane (e.g. lysosome, mitochondrion).
Orthodontic – pertaining to the division of dentistry dealing with prevention and correction of abnormally positioned or aligned teeth.
Orthopedic – pertaining to the branch of medicine dealing with correction of disorders involving locomotor structures of the body (skeleton, joints, muscles, ligaments, cartilage, etc.).
Orthosis – a device applied externally to the body to provide stability and to control motion; may or may not replace a portion of a limb . See also exoprosthesis.
Orthostatic – pertaining to an erect position of the body.
Orthotopic – graft of an organ to a site where that organ would normally be present; in the correct place.
OSHA – Occupational Safety and Health Administration (U.S.).
Osmotic pressure – the pressure that would develop if a solution is enclosed in a solvent-permeable membrane that is impermeable to all solutes present, and is then surrounded by pure solvent.
Osseocompatibility – biocompatibility with bone.
Osseointegration (osteointegration) – clinical stability of an implant anchored in bone, often in reference to implants with bioactive coatings; a description of the clinical performance of devices, not the biomaterial-bone interaction .
Osseous (also osteo-) – pertaining to bone.
Ossicle (ossicular) – any small bone, especially one of the three bones of the ear.
Osteoblast – a bone-forming cell derived from mesenchyme to form the osseous matrix in which it becomes enclosed as an osteocyte.
Osteoclast – a giant multinuclear cell with abundant acidophilic cytoplasm, formed in the bone marrow of growing bones, which functions to absorb and remove unwanted osseous tissue.
Osteoconductive – property of a biomaterial that encourages bone, already being formed, to lie closely to or adhere to its surface .
Osteocyte – a mesodermal bone-forming cell that has become entrapped within the bone matrix, helping to maintain bone as living tissue.
Osteodystrophy – defective bone development.
Osteogenic – property of a biomaterial that stimulates bone growth in the implant site .
Osteolysis (“small-particle disease”) – cellularly-mediated bone loss secondary to debris production or release by implants in or near to bone, previously incorrectly called “cement disease” .
Osteomalacic – concerning or characterized by softening of the bone.
Osteopontin – a calcium-binding phosphoprotein synthesized by pre-osteoblasts, osteoblasts and osteocytes that is important in bone remodeling and various immunological functions, and is believed to play a role in several different cellular processes; a protein found in healing wounds.
Osteoporosis – any disease process that results in the mass of bone per unit of volume.
Osteotomy – the operation for cutting through a bone.
Ostium (ostia) – small opening(s), especially one into a tubular organ.
Otosclerosis – chronic progressive deafness.
Outmessaging – in medical nanorobotics, conveyance of information from a transmitter located inside the human body, especially from working nanodevices, to the patient or to a recipient external to the human body (Section 184.108.40.206).
Pacemaker, artificial – an electrical device that can substitute for a defective natural pacemaker and control the beating of the heart by a series of rhythmic electrical discharges.
Palpebral – pertaining to an eyelid.
PAM – pulmonary alveolar macrophage.
Pancreatic islet cells – clusters of cells in the pancreas (islets of Langerhans); destruction or impairment may result in diabetes or hypoglycemia.
Pannus – newly formed superficial vascular tissue over the cornea.
Parasitophorous – containing a parasite.
Paratope – the site on an antibody to which an antigen attaches.
Parenchyma – the essential parts of an organ that are concerned with its function as opposed to its framework; opposite of stroma. The distinguishing or specific cells of a gland or organ, contained within and supported by the connective tissue framework.
Parenteral – denoting any medication route other than the alimentary canal, such as intravenous, subcutaneous, intramuscular, or mucosal.
Paresthesia – sensation of numbness, prickling, or tingling.
Parietal – pertaining to, or forming, the walls of a cavity; often specifically refers to the parietal bone, one of two bones that together form the roof and sides of the skull.
Parkinson’s disease – chronic nervous disease characterized by a fine, slowly spreading tremor, muscular weakness and rigidity, and a peculiar gait.
Passivation – the covalent bonding of a layer of atoms to a surface, in order to neutralize (occupy) any dangling surface bonds, thus chemically stabilizing the surface.
Patch clamp – method of measuring ion currents in individual cells.
Patella – lens-shaped sesamoid bone situated in front of the knee in the tendon of the quadriceps femoris muscle.
Patency – the state of being freely open.
Pathogen – a microorganism or agent capable of producing disease.
Pathogenic – productive of disease.
Pathognomonic – characteristic or indicative of a disease; relating to one or more of the typical symptoms of a disease.
Pathological – diseased or due to a disease; more informally, pertaining to an adverse condition.
Pathophysiology(ic) – study of how normal physiological processes are altered by disease.
Patocytosis – a unique macrophage endocytotic pathway in which external particles induce and enter a labyrinth of internal membrane-bound compartments that remain connected to the phagocytic cell surface.
PCV – postcapillary venules.
PDMS – Polydimethylsiloxane elastomer.
PEG – polyethylene glycol.
Pegylated – containing a surface coating of PEG.
PEI – polyethylenimine.
PEO – polyethylene oxide.
Peptide – a short chain of amino acids joined by amide bonds, up to 100 residues in length.
Percussion (percussive) – hitting or impact of one body against another, and the resulting shock, vibration or sound.
Percutaneous device – a medical device that passes through the skin, remaining in position for a significant length of time .
Perianal – near the anus.
Pericardium – the double membranous fibroserous sac enclosing the heart and the origins of the great blood vessels.
Pericyte – a flat, undifferentiated, contractile connective tissue cell around the capillary walls.
Peri-implant – near the implant.
Perinuclear – near the cell nucleus.
Perineurally – near a neuron.
Periodontal – located around a tooth.
Peripartum – near or around the time of birth.
Periportal – near the portal end.
Perirobotic – near or around a robot.
Peristalsis – a progressive wavelike movement that occurs involuntarily in hollow tubes of the body, especially the alimentary canal; it is characteristic of tubes possessing longitudinal and circular layers of smooth muscle fibers.
Peristaltogenesis – eliciting peristalsis.
Peritoneum – in anatomy, the serous membrane reflected over the viscera and lining the abdominal cavity.
Peritonitis – inflammation of the peritoneum, the membranous coat lining the abdominal cavity and investing the viscera.
Peritrichous – indicating microorganisms that have cilia or flagella covering the entire surface.
Periurethral – in anatomy, located near or around the urethra (which discharges urine).
Permucosal device – a medical device that passes through a mucosal layer, remaining in position for a significant length of time .
Peroperative – during or through an operation.
Peroxisome (peroxisomal) – in cell biology, an organelle found in vertebrate animal cells that contains a great number and variety of enzymes important in cell metabolism (Section 220.127.116.11).
Pertussis – an acute, infectious disease characterized by a catarrhal stage, followed by a peculiar paroxysmal cough, ending in a whooping inspiration.
Peyer’s patches – an aggregation of lymph nodules found chiefly in the ileum near its junction with the colon.
pH – potential of hydrogen; measure of the degree of alkalinity or acidity.
Phage – see bacteriophage.
Phagocyte – a cell with the ability to ingest and destroy particulate substances such as bacteria, protozoa, cells and cell debris, dust particles, and colloids (Section 18.104.22.168).
Phagocytocide – killing phagocytes.
Phagocytosis – ingestion and digestion of bacteria and particles by phagocytes. The process of internalizing small particles by mammalian cells .
Phagocytosis, frustrated – the failure of mammalian cells to phagocytose particles due primarily to their size, resulting in release of cytokines .
Phagolysosome – the body formed when the membrane-bound phagosome inside a macrophage fuses with a lysosome.
Phagosome – a membrane-bound vacuole inside a phagocyte that contains material waiting to be digested.
Phalanx – any one of the bones of the fingers or toes.
Pharmacokinetics – study of the metabolism of drugs with particular emphasis on the time required for absorption, duration of action, distribution in the body, and method of excretion. See also ADME.
Pharmacyte – in medical nanorobotics, a theorized (nanorobotic) device capable of delivering precise doses of biologically active chemicals to individually-addressed human body tissue cells (e.g. cell-by-cell drug delivery) (Section 10.4.1.4, Chapter 19).
Pharynx (pharyngeal) – the passageway for air from the nasal cavity to the larynx (also acting as a resonating cavity), and for food from the mouth to the esophagus; more specifically, a musculomembranous tube extending from the base of the skull to the level of the 6th cervical vertebra, where the tube becomes continuous with the esophagus.
Phenotype – the appearance or other characteristics of an organism, resulting from the interaction of its genetic constitution with the environment; any observable characteristic that expresses the genotype of an individual.
Phlebitis – inflammation of a vein.
Phlogistic – pertaining to, or inducing, inflammation.
Phospholipid – a lipoid substance containing phosphorus and fatty acids; major component of cell plasma membrane.
Phosphorylation – the combining of a phosphate with an organic compound.
Photic – pertaining to visible light.
Photopheresis – extracorporeal photochemotherapy (ECP) , a novel immunomodulatory therapy based on pheresis of light-sensitive cells.
Phytotoxic – pertaining to a poisonous plant.
Pial – concerning the pia mater membrane investing the brain and spinal cord.
Pica – an eating disorder manifested by a craving to ingest any material not fit for food, including starch, clay, ashes, toy balloons, crayons, cotton, grass, cigarette butts, soap, twigs, wood, paper, metal, or plaster. This condition is seen in pregnancy, chlorosis, hysteria, helminthiasis, certain psychoses, and may be associated with iron deficiency anemia.
Pili (fibriae) – hairs or filamentous appendages.
Pinealocytes – the principal cell of the pineal body (a glandlike structure in the brain).
Pinocytosis – the process by which cells absorb or ingest nutrients and fluid, in which minute incuppings or invaginations are first formed in the surface of the plasma membrane and then close to form fluid-filled vesicles; resembles phagocytosis.
PLA – polylactic acid.
Planktonic cells – individual free-floating cells, especially microorganisms, released from a biofilm.
Plasma – in anatomy, the fluid (noncellular) part of the lymph and of the blood, usually distinguished from the serum obtained after coagulation; in cell biology, the part of the protoplasm (cell substance) outside of the nucleus.
Plasma cell (plasmacyte) – cell found in connective tissue, having an eccentrically placed round nucleus filled with a chromatin mass.
Plasmalemmal – pertaining to the cell plasma membrane.
Plasma membrane – the outermost membrane of a cell, with cell contents on one side and the extracellular environment on the other side; the continuous membrane defining the boundary of every cell (Section 22.214.171.124).
Plasmapheresis – see apheresis.
Plasmatic layer/zone – a cell-free zone near the vascular luminal wall that forms a thin lubrication layer (Section 126.96.36.199).
Plasmid – an autonomous self-replicating extrachromosomal circular DNA molecule present intracellularly and symbiotically in most bacteria, encoding a protein product that confers drug resistance or some other advantageous phenotype. Plasmids reproduce inside the bacterial cell but are not essential to its viability, and can influence a great number of bacterial functions.
Plasmin – fibrinolytic enzyme derived from its precursor plasminogen.
Plasminogen – protein found in many tissues and body fluids, important in preventing fibrin clot formation.
Plastizymes – plastic polymer enzyme mimics.
Platelet – a round or ovoid 2-4 micron disk found in the blood of vertebrates; platelets play an important role in blood coagulation and hemostasis.
Plectin – a cytoskeleton associated protein.
Pledgets – small, flat compress, usually of gauze or absorbent cotton, used to absorb or apply fluid, to protect, or to exclude air.
Pleocytosis – increased number of lymphocytes in the cerebrospinal fluid.
Pleura – serous membrane that enfolds both lungs and is reflected upon the walls of the thorax and diaphragm; membrane is moistened with a serous secretion that reduces friction during respiratory movements.
PLG – poly lactide co-glycolide.
Ploidy – the number of chromosome sets in a cell.
PMMA – polymethylmethacrylate.
PMN – polymorphonuclear leukocyte; see granulocyte.
Pneumoconiosis – a pathological condition of the respiratory tract due to inhalation of dust particles.
Pneumothorax – a collection of air or gas in the pleural cavity.
Poiseuille fluid flow – laminar flow in a pipe (Section 9.2.5).
Polarization – in biology and electrical physics, the development of differences in electrical potential between two points on an object, such as between the inside and outside of a cell wall or along the length of a piezoelectric bone subjected to shear stress.
Polyanion – molecule containing multiple anions. See also anion.
Polycation – molecule containing multiple cations. See also cation.
Polycythemia – an excess of red blood cells.
Polymer – a long molecular chain of well-defined linked subunits.
Polymorphonuclear leukocyte – see granulocyte.
Polysaccharide – complex carbohydrates of high molecular weight; one of a group of carbohydrates that upon hydrolysis yields more than two molecules of simple sugars.
Polystyrene – a synthetic resin produced by the polymerization of styrene from ethylene and benzene.
Porcine – related to or derived from pig.
Porins – channel proteins which establish a pore in a cell plasma membrane, allowing cytosolic molecules to pass out of the cell.
Posterior – the backside of the human body; the backside of something.
Postmortem – after death.
Postpartum – after childbirth.
Postprandial – after a meal.
Postrema, area – a circumventricular organ located in the medulla of the brain.
Presentation semaphore – in medical nanorobotics, a mechanical device used to display specific antigens, chemical ligands, or other molecular objects to the external environment, with the purpose of selectively modifying the chemical or other surface characteristics of a nanorobot exterior (Section 5.3.6).
Prionosis – pathological protein folding conformations.
Prokaryote (prokaryotic) – in microbiology, an organism or cell that lacks a nucleus.
Prolate spheroid – football-shaped.
Prostaglandins – large group of biologically active unsaturated fatty acids that represent some of the metabolites of arachidonic acid, and act as local intercellular or intracellular modulators of biochemical activity.
Prosthesis – replacement of missing part with an artificial substitute, such as an artificial extremity; an artificial organ or part; device to augment performance of a natural function. See also endoprosthesis, exoprosthesis; compare orthosis.
Protease – a class of enzymes that break down, or hydrolyze, the peptide bonds that join the amino acids in a protein.
Protein – a long chain of amino acids joined by amide bonds, exceeding 100 residues in length; shorter chains are peptides. More generally, living cells contain many molecules that consist of amino acid polymers folded to form more-or-less definite three-dimensional structures, termed proteins. Short polymers lacking definite three-dimensional structures are termed peptides. Many proteins incorporate structures other than amino acids, either as covalently attached side chains or as bound ligands. Molecular objects made of protein form much of the molecular machinery of living cells.
Proteoglycans – the predominant, non-collagenous component of cartilage matrix; large molecules with a central protein core and attached polysaccharide molecules extending from the core like bottle brush bristles; aka. acid mucopolysaccharide.
Proteolysis (proteolytic) – hydrolysis (breakdown) of proteins, usually by enzyme action, into simpler substances.
Proteophilic – tending to attract proteins.
Proteophobic – tending to repel proteins.
Protozoa – the simplest animals, mostly unicellular although some are colonial. Compare metazoa.
Proximal – near the source or point of attachment or origin; in the extremities, closer to the trunk.
Pruritus (pruritic) – itching.
Pseudointima – tissue consisting of a firm fibrin clot with occasional islands of endothelial cells, formed by the resolution of inflammation on interior (blood-contacting) surfaces of cardiovascular implants .
Pseudoneointima – pseudointima in which cells form a continuous layer .
Pseudopod – in microbiology, a temporary protruding protoplasmic process in protozoa for the purpose of taking up food and aiding in locomotion.
Psychogenic – of mental origin.
Psychosomatic – pertaining to the influence of the mind or of higher functions of the brain upon the functions of the body, especially in relation to bodily disorders or disease.
PTFE – polytetrafluoroethylene (a form of Teflon).
Pulmonary – pertaining to the lungs.
Purkinje neurons – large neurons that have dendrites extending to the molecular layer of the cerebellar cortex and into the white matter of the cerebellum.
PVC – polyvinyl chloride.
Pyoinflammatory disease – inflammation involving pus formation.
Pyrexia – fever.
Pyrogen – a substance producing fever in vivo.
Pyrolysis – decomposition of organic matter when there is a rise in temperature.
Pyrolytic carbon – carbon formed in a fluidized bed by the pyrolysis of a gaseous hydrocarbon such as methane, depositing carbon onto a preformed substrate such as polycrystalline graphite at 1000-1500 K (Section 188.8.131.52).
Pyropoikilocytosis – a severe form of congenital hemolytic anemia clinically similar to, and now considered a subtype of, homozygous hereditary elliptocytosis. The disorder produces a molecular defect in spectrin and a partial spectrin deficiency, manifesting as a severe hemolytic anemia with thermal instability of the red cells.
Pyuria – pus in the urine.
Quantum dots – nanocrystalline semiconductor particles used for testing and diagnosis (Section 184.108.40.206); a zero-dimensional quantum system.
Quantum yield – The number of defined events which occur per photon absorbed by the system.
Radical – in chemistry, a group of atoms acting as a single unit, passing without change from one compound to another, but unable to exist in a free state.
Radioimmunoassay – a very sensitive method for determining the concentration of substances, particularly the protein-bound hormones, in blood plasma.
Ramus – a branch; one of the divisions of a forked structure.
RBC – red blood cell (erythrocyte).
Receptor – most generally, a structure that can capture a molecule (often of a specific type in a specific orientation) owing to complementary surface shapes, charge distributions, and so forth, without forming a covalent bond. In biology, a receptor is a transmembrane protein, located in the plasma membrane, that binds a ligand in a domain on the extracellular side, and as a result has a change in activity of the cytoplasmic domain of the protein.
Red blood cell (RBC) – see erythrocyte.
Reference material – a material that, by standard test, has been determined to elicit a reproducible, quantifiable host or material response 
Reflex sympathetic dystrophy (RSD) – a neurovascular complication of CVA (cerebrovascular accident) characterized by severe shoulder pain and stiffness, swelling and pain in the hand.
Renal – pertaining to the kidney.
Replant biomaterials – see biomaterials, replant.
RES – see reticuloendothelial system.
Resection – the partial excision of a bone or other structure.
Resolution (of inflammation) – the stable end state of the inflammation or inflammatory response associated with an implant .
Resorbable (resorption) – the ability of a biomaterial to be dissolved or digested, and thus disappear after implantation; does not imply specific action of cells or tissues . See also bioresorbable.
Respirocyte – in medical nanorobotics, a theorized bloodborne spherical 1-micron (nanorobotic) device having a 1000-atm pressure vessel with active pumping powered by endogenous serum glucose, that serves as a mechanical artificial red blood cell  (Chapter 22).
Response, immune – see immune response.
Response, inflammatory – see inflammatory response.
Restenosis – the recurrence of a stenosis condition, e.g., in a heart valve or blood vessel.
Reticulation – the formation of a network mass.
Reticulocyte – a red blood cell containing a network of granules or filaments representing an immature stage in development.
Reticuloendothelial system (RES) – in anatomy, the network of fixed and mobile phagocytes that engulf (and dispose of) foreign antigens and cell debris found inside the human body. The reticuloendothelium is the tissue of the reticuloendothelial system (RES); the system of mononuclear phagocytes located in the reticular connective tissue of the body that is responsible for the phagocytosis of damaged or old cells, cellular debris, foreign substances, and pathogens, removing them from the circulation (Section 220.127.116.11).
Retrograde – moving backward.
Reynolds number – the ratio of inertial to viscous forces in fluid flow. Macroscopic objects and flows typically experience Reynolds numbers >> 1, where mass and inertia dominate object motions; microscopic and especially nanoscale objects and flows typically experience Reynolds numbers << 1, where the viscosity of the environment dominates object motions (Section 18.104.22.168).
rf – radio frequency.
RGD – the peptide fragment arginine-glycine-aspartic acid.
Rhegmatogenous – originating or due to a rhegma (rupture, fracture, or rent).
Rheology (rheological) – study of the deformation and flow properties of materials, especially fluids, such as blood.
Rheumatoid arthritis – form of arthritis with inflammation of the joints, stiffness, swelling, cartilaginous hypertrophy, and pain.
Rhinitis – inflammation of the nasal mucosa.
Ribonucleic acid (RNA) – the ribonucleotide polymer into which DNA is transcribed.
Ribosome – a naturally occurring molecular machine that manufactures proteins according to instructions derived from the cell’s genes; a cytoplasmic ribonucleoprotein complex that serves as the site of translation in the cell. Each ribosome has a large and a small subunit, 60S and 40S in eukaryotes. These subunits dissociate and reassociate in a cycle related to their functions, during translation.
Ribotoxic – toxic to ribosomes.
RNA – see ribonucleic acid.
RNA polymerase – an enzyme that synthesizes RNA under direction from a DNA template (formally described as DNA-dependent RNA polymerase).
Robot – a programmable device usually consisting of mechanisms for sensing and mechanical manipulation, often connected to (or including) a computer that provides control.
Rosai-Dorfman disease – sinus histiocytosis with massive lymphadenopathy; commonly presents as massive, painless, bilateral lymph node enlargement in the neck, with fevers.
Rouleaux – stack-of-coins configuration of a cluster of red blood cells.
Rubor – local tissue reddening, one of the four classic signs of inflammation (Section 15.2.4); see also calor, dolor, tumor.
Ruffini endings – encapsulated sensory nerve endings found in subcutaneous tissue.
Rugosity – condition of being folded or wrinkled; surface roughness.
Ruminant – an animal that regurgitates food in order to chew it again.
Russell bodies – small spherical hyaline bodies in cancerous and simple inflammatory growths.
Sacrum – triangular bone made up of five fused vertebrae just above the coccyx.
Sagittal – in anatomy, a vertical plane or section that divides the body into right and left portions.
Saltatory – hopping or leaping.
Saphenous veins – two superficial veins passing up the leg (Figure 8.2).
Sarcoma – cancer arising from connective tissue such as muscle or bone.
Sarcolemma – a delicate membrane surrounding each striated muscle fiber.
Schistocyte (schistocytic) – an irregularly contracted fragmented red cell (Section 22.214.171.124.1).
Schistosomiasis – a parasitic disease due to infestation with blood flukes (schistosomes); endemic throughout Asia, Africa, and tropical America.
Schizont – stage in asexual phase of life cycle of Plasmodium organisms found in red blood cells.
Schlemm’s canal – irregular space or spaces in the scerocorneal region of the eye, that receives the aqueous humor from the anterior chamber of the eye.
Schwann’s cells – cells of ectodermal (outer cell layer of developing embryo) origin that comprise neurilemma (a thin membranous sheath enveloping a nerve fiber).
Scission – dividing, cutting, splitting, or pinching off.
Sclera (eye) – tough white fibrous tissue covering the white of the eye, extending from the optic nerve to the cornea.
Sclerosis (sclerotic) – hardening of a tissue or organ, especially due to excessive growth of fibrous tissue; also, thickening and hardening of the tissue layers comprising the walls of an artery.
SDS – sodium dodecyl sulfate, an anionic detergent commonly used to solubilize proteins.
Secretagogue – agent that induces secretion.
Selectins – a family of ~50 kilodalton cell adhesion receptor glycoprotein molecules that can recognize diverse cell-surface antigen carbohydrates and help localize leukocytes to regions of inflammation (leukocyte trafficking). Selectins are not attached to the cytoskeleton.
SEM – scanning electron microscope.
Semaphores – see presentation semaphores.
Sepsis – the presence of various pus-forming and other pathogenic organisms, or their toxins, in the blood or tissues.
Septic – pertaining to or caused by sepsis.
Septic shock – signs of acute septicemia combined with hypotension and signs of inadequate organ perfusion (Section 126.96.36.199).
Septicemia – septic fever; systemic disease caused by the multiplication of microorganisms in the circulating blood.
Septum, atrial – a wall between the atria of the heart.
Sequela – a condition following and resulting from a disease.
Sequestration – isolation and temporary storage in cells or tissues.
Sequestrum – a mineralized capsule; see incapsulation.
Serine – an amino acid present in many proteins.
Serotonin – a biochemical substance, 5-hydroxytryptamine (5-HT), that is present in platelets, gastrointestinal mucosa, mast cells, and in carcinoid tumors. Serotonin is a potent vasoconstrictor involved in neural mechanisms important in sleep and sensory perception.
Serotype – in microbiology, a microbe determined by the kinds and combinations of constituent antigens present in the cells.
Serous membrane – a membrane lining a serous cavity, specifically the pleural (lung), peritoneal (abdominal), and pericardial (heart) cavities.
Serum – the watery portion of the blood after coagulation; a fluid found when clotted blood is left standing long enough for the clot to shrink. More generally, any serous fluid, especially the fluid that moistens the surfaces of serous membranes.
Sessile – incapable of voluntary movement. Opposite of motile.
Shear stress, fluid – lateral force per unit area imposed by transversely-moving fluids that generate shear forces (Section 188.8.131.52).
Shock, anaphylactic – see anaphylaxis.
Shock, nanoid – see nanoid shock.
Shock lung – aka. acute respiratory distress syndrome (ARDS), a syndrome of severe respiratory failure associated with pulmonary infiltrates similar to infant hyaline membrane disease.
Sialolithiasis – presence of salivary calculi.
Sialyl – a glycoprotein moiety. Compare asialo-.
Singlet oxygen – an electronically-excited chemically-reactive form of oxygen.
Sinusoid – resembling a sinus (a cavity having a relatively narrow opening); a minute blood vessel found in such organs as the liver, spleen, adrenal glands, and bone marrow, that is slightly larger than a capillary and has a lining of reticuloendothelium.
SMC – smooth muscle cell.
Small-particle disease – see osteolysis.
Somatic – in general, relating to the body, as opposed to the mind or soul; corporeal.
Sonication – to bombard with high-energy acoustic waves, often for the purpose of fragmenting or destroying the sonicated object.
Sorboregulatory – in medical nanorobotics, active regulation of the adsorptive characteristics of the nanorobot surface, allowing in situ regulation of the selective binding characteristics of surfaces (Section 184.108.40.206). See also adhesioregulatory.
Sorting rotor – see molecular sorting rotor.
sp2/sp3 – in carbon solids, graphite-like (sp2) or diamondlike (sp3) bonding, respectively.
Spectrin – an actin-binding peripheral protein found in the erythrocyte membrane skeleton.
Spherocyte – an erythrocyte that assumes a spheroid shape.
Spindle – bundle of delicate fibrils that connect the two centrosomes; seen during mitosis.
Spirochete – any member of the order Spirochaetales.
Splanchnic – pertaining to the viscera.
Splanchnodynia – abdominal pain.
Splanchnomegaly – abnormal distension of the viscera.
Splenectomy – surgical removal of the spleen.
Splenic – pertaining to the spleen.
Splenofenestral motility – in medical nanorobotics, the ability to actively locomote through the fenestral slits in the spleen.
Splenomegaly – abnormal enlargement of the spleen.
SPM – scanning probe microscope (microscopy); suspended particulate matter (environmental health).
Spontaneous arterial dissection – a tear in the intima of the blood vessel, allowing blood to dissect the wall of the artery; occurs in the absence of external trauma.
Squamous cell – a flat, scaly epithelial cell.
Standard test – a well-defined, repeatable test (Section 220.127.116.11) of host response or material response, generally involving the use of one or more reference materials .
Starch – noncrystalline carbohydrate of the polysaccharide group found in plants.
Stasis – stagnation of normal flow of fluids or of the intestinal mechanism; ceasing of activity.
Stellate – star-shaped.
Stem cells – a cell that gives rise to a specific type of cell as in hematopoiesis.
Stenosis (stenotic) – constriction or narrowing of a passage or orifice.
Stent – any material used to hold tissue in place or to provide a support for a graft during healing; a flexible metal coil or open-mesh tube surgically inserted into a narrowed artery.
Stercoral – pertaining to feces.
Stereocilia, cochlear – specialized mechanoreceptor cells of the inner ear.
Steric – pertaining to the spatial relationships among atoms in a molecular structure; in particular, pertaining to the space-filling properties of a molecule.
Steric hindrance (barrier) – in chemistry, slowing of the rate of a chemical reaction owing to the presence of molecular structures possessed by the reagents that mechanically interfere with the motions associated with the reaction, typically by obstructing the reaction site; in hematodynamics, the reduction in hematocrit near small blood vessel bifurcations due to the elongation and orientation of red cells along the direction of shear flow.
Sternum (sternal) – pertaining to the breastbone.
Sternutation – sneezing.
Sternutogenesis – producing sneezing (Section 18.104.22.168).
Steroids – a large family of chemical substances, comprising many hormones, vitamins, body constituents, and drugs, each containing the tetracyclic cyclopentophenanthrene skeleton.
STM – scanning tunneling microscope.
STOC – spontaneous transient outward currents.
Stoichiometric – in chemistry, pertaining to the precise quantities of reagents required to complete a chemical reaction; in particular, to the exact amounts needed to balance the chemical reaction equation.
Stroma – foundation-supporting tissues of an organ, defining the framework of an organ; opposite of parenchyma.
Subarachnoid space – space between the pia proper and arachnoid containing the CSF.
Subareolar – below the areola.
Subclavian – under the clavicle (collarbone).
Subcutaneous (subcutis) – beneath, or to be introduced beneath, the skin.
Sublimation – in chemistry, passing directly from solid to vapor state.
Submasseteric – lying underneath the masseter (the muscle that closes the mouth and the principal muscle in mastication).
Subperiosteal – beneath the periosteum (fibrous membrane covering bone).
Sulcus – furrow, groove, fissure, or slight depression.
Superior – upper or higher than; situated above something else
Supine – lying on the back, with the face up.
Surfactant – in physical chemistry, a chemical agent that lowers surface tension.
Swine – pertaining to pigs.
Sympathomimetic – adrenergic.
Synapse (synaptic) – the point of junction between two neurons in a neural pathway, where the termination of the axon of one neuron comes into close proximity with the cell body or dendrites of another neuron.
Syncope – transient loss of consciousness due to inadequate blood flow to the brain.
Synechias – adhesions of parts, especially adhesion of iris to lens and cornea.
Synovial – pertaining to the capsule of a skeletal joint.
Synoviocyte – cells comprising the intima of synovial membrane (tissue lining the noncartilaginous surfaces of a synovial joint); cells are of two types, macrophage-like and fibroblast-like.
Systole (systolic) – the normal period in the heart cycle during which the muscle fibers tighten and shorten, the heart constricts, and the cavities empty of blood; roughly, the period of contraction alternating with diastole or relaxation. Occurs in the interval between the first and second heart sounds during which blood is surged through the aorta and pulmonary artery.
Tachyphylaxis – the rapid desensitization to a toxic substance produced by inoculation with a series of small doses, or a rapidly decreasing response to a drug following administration of the initial doses.
Tamponade, cardiac – pathological condition resulting from accumulation of excess fluid in the pericardium.
Tay-Sachs disease – inherited autosomal-recessive disease; neurological deterioration characterized by mental and physical retardation, blindness, spasticity, etc.
Teflon – a polymeric fluorocarbon (Section 15.3.4).
Teflonoma – large granuloma formed in reaction to Teflon.
Tegument – the skin or covering of a living body.
Telomere – the natural end of a chromosome; the telomeric DNA sequence consists of a simple repeating unit (in humans, TTAGGG) with a protruding single-stranded end that may fold into a hairpin.
TEM – transmission electron microscope.
Tendon – fibrous connective tissue serving for the attachment of muscles to bones and other parts.
Tensegrity – cell shape maintenance by a tensional integrity architecture that achieves mechanical stability because of the way compressive and tensional forces are distributed and balanced within the cell.
Terabot – a trillion (1012) medical nanorobots, usually in reference to dosage.
Teratogenicity – producing abnormal development in an embryo.
Tetramer – polymer comprised of 4 units.
Thermal conductivity – transport of thermal energy due to a temperature gradient; the energy flux (W/m2) per unit of spatial temperature gradient (K/m) equals the coefficient of thermal conductivity (W/m-K).
Thermocompatibility – the thermal biocompatibility of nanodevices or nanorobotic systems as they interact with the organs, tissues and cells of the human body (Section 15.3.8).
Thermogenic limit – in medical nanorobotics, the maximum amount of waste heat that may safely be released by a population of in vivo medical nanorobots that are operating within a given tissue volume (Section 6.5.2).
Thiol group – in chemistry, an -SH group, or a molecule containing such a group; also known as a sulfhydryl or mercapto group.
Thorax (thoracic) – that part of the body between the base of the neck superiorly and the diaphragm inferiorly.
Thrombocyte – platelet.
Thrombocytolysis – fragmentation of platelets.
Thrombocytopenia – reduced platelet count.
Thromboembolus – blocking of a blood vessel by a thrombus that has detached from its site of formation.
Thrombogenicity – the property of a material that induces or promotes the formation of a thrombus .
Thrombogenicity (inherent) – thrombus formation controlled by the material surface ; reaction-controlled thrombogenicity at the surface of a material .
Thromboresistant – see nonthrombogenic.
Thrombosis – formation, development, or existence of a blood clot or thrombus within the vascular system.
Thrombotic thrombocytopenic purpura (TTP) – a rare disease characterized by embolism and thrombosis of small blood vessels.
Thrombus – a solid mass formed from the molecular and cellular constituents of blood ; a blood clot.
Thymocyte – a cell in the thymus that migrated there from the bone marrow, ultimately to become various types of T lymphocytes.
Tibia – the inner and larger bone of the leg between the knee and the ankle.
Tingible – capable of being stained by a dye.
Tissue engineering – elaboration of cells and tissues outside a living organism, intended for use as components of a viable biomaterial or replant, by use of engineering methods and techniques .
Tissue response – see host response, local.
TLV – threshold limit value  (OSHA).
T-lymphocytes (T-cells) – White blood cells that are produced in the bone marrow but later mature in the thymus. T-cells are important in the body’s defense against certain bacteria and fungi, help B-cells make antibodies, and assist in the recognition and rejection of foreign tissues.
TNF – tumor necrosis factor.
Tolerogen – a material which can induce immunological tolerance or unresponsiveness .
Tophi – large crystalline deposits.
Toxic shock – a disease caused by the release of toxins produced by certain strains of various bacteria.
Trabecula – fibrous cord of connective tissue, serving as support, forming a septum extending into an organ from its wall or capsule.
Trachea(l) – a cylindrical cartilaginous tube extending from the larynx to the bronchial tubes.
Tracheobronchial – concerning the trachea and bronchus.
Transcription – synthesis of RNA on a DNA template.
Transcutaneous (percutaneous) – effected through the skin.
Transcytosis – passage through cellular membrane or tissue wall barriers.
Transendothelial – see diapedesis.
Transepithelial – crossing an epithelial layer.
Transferrin – a globulin in the blood that binds and transports iron.
Translation – in biochemistry, the synthesis of protein on the mRNA template; the process of reading the codon sequence in mRNA to synthesize the corresponding polypeptide with the involvement of ribosomes, tRNA, and many enzymes.
Translocation – movement across intestinal walls or into lung interstitium.
Transmigration – see diapedesis.
Transposon – a genetic unit such as a DNA sequence that is transferred from one cell’s genetic material to another.
Trigeminal – pertaining to the trigeminus or fifth cranial nerve.
Trillion – this book follows the American convention in which a trillion is 1012.
Trophozoite – a sporozoan nourished by its hosts during its growth stage.
Trypanosomiasis – any disease caused by trypanosomes (asexual protozoan flagellates parasitic in the blood plasma of many vertebrates).
Tuboplasty – plastic repair of any tube.
Tubulin – a protein present in the microtubules of cells, which are polymers of alpha tubulin (~53,000 dalton) and beta tubulin (~55,000 dalton) dimers.
Tumor (cancer) – spontaneous new growth of tissue forming an abnormal mass.
Tumor (inflammation) – local tissue swelling, one of the four classic signs of inflammation (Section 15.2.4); see also calor, dolor, rubor.
Tumorigenic – producing a tumor.
Turbulence – in hydrodynamics, fluid flow which does not follow parallel streamlines, which has a blunt (nonparabolic) profile in tube flow, and often involves eddies, vortices, and significant variations in fluid velocities, accelerations and shear stress between adjacent fluid elements. Turbulence dissipates more energy, and presents more resistance to flow, than laminar flow.
Turgor – distension, swelling.
TWA – time-weighted average  (OSHA).
Tympanoplasty – surgical procedure to cure inflammatory process or restore function in the ear.
Ubiquitin – a small protein present in eukaryotic cells that combines with other proteins and makes those other proteins susceptible to destruction; this protein is also important in promoting the functions of proteins that make up the ribosomes.
Ulcer – an open sore or lesion of the skin or mucous membrane accompanied by sloughing of inflamed necrotic tissue.
Ulceration (ulcerative) – suppuration occurring on a free surface, as on the skin or a mucous membrane, to form an ulcer.
ULTI carbon – ultra-low-temperature isotropic carbon (Section 22.214.171.124).
Undifferentiated – alteration in cell character to a more embryonic type or toward a malignant state.
Urate – a salt of uric acid.
Uremia – toxic condition associated with renal insufficiency produced by retention in the blood of nitrogenous substances normally excreted by the kidney.
Urethra – a canal for the discharge of urine extending from the bladder to the outside of the body.
Urticaria – vascular reaction of the skin characterized by the eruption of pale evanescent wheals (round elevations of the skin, white in the center with a pale red periphery), which are associated with severe itching; hives.
UTP – uridine triphosphate; analog to ATP.
Uveitis – a nonspecific term for any intraocular inflammatory disorder, usually of the uveal tract structures (iris, ciliary body, and choroid, forming the pigmented layer) although nonuveal parts such as the retina and cornea may also be involved.
Vacuole – a clear space in cell protoplasm filled with fluid or air.
Vagus – the tenth cranial nerve.
Valsalva, sinuses of – three dilations in wall of the aorta behind the flaps of the three aortic semilunar valves.
Van der Waals forces – weak electrostatic forces between atoms and molecules; any of several intermolecular attractive forces not resulting from ionic charges; also known as the London dispersion force (Section 3.5.1).
Vasa vasorum – the microvasculature of the aorta.
Vascular – containing, or pertaining to, blood or lymph vessels.
Vascular gate – a vascular plug or selective gate spanning the lumen of a blood, lymph, or other fluid vessel, for the purpose of allowing only specified particulate matter to pass, or selectively filtering out other specified particular matter or fluids (Section 126.96.36.199; Chapter 19).
Vasculitis – inflammation of a blood or lymph vessel.
Vasculoid – in medical nanorobotics, an intimate personal appliance that conforms to the shape of existing blood vessels and augments the human vascular system, replacing blood with a single, complex robot that can duplicate all essential thermal and biochemical transport functions of the blood, including circulation of respiratory gases, glucose, hormones, cytokines, waste products, and all necessary cellular components; a member of a class of space- or volume-filling nanomedical augmentation devices whose function applies to the human vascular tree  (Chapter 30).
Vasculomobility – in medical nanorobotics, capable of locomotion along, across, or through vascular walls.
Vasculopathy – any disease of blood vessels.
Vas deferens – the excretory duct of the testis.
Vasoconstriction – in physiology, a decrease in the diameter of blood vessels.
Vasodilation – in physiology, an increase in the diameter of blood vessels.
Vasorelaxation – lessening of vascular pressure.
Ventricle (ventricular) – either of two lower chambers of the heart.
Vermiformis – contoured like a worm.
Vermipodia – worm-like processes observed on cell surfaces in a few cases of malignant histiocytosis and a case of leukemic reticulum-cell sarcoma .
Vertigo – the sensation of moving around in space; sometimes used as a synonym for dizziness, lightheadedness, or giddiness.
Vesicles – small bodies bounded by membrane, derived by budding from one membrane and often able to fuse with another membrane.
Vesicles (endocytotic) – membranous particles that transport proteins through endocytosis; also known as clathrin-coated vesicles, having on their surfaces a layer of the protein clathrin.
Vesicles (exocytic) – membranous particles that transport and store proteins during exocytosis.
Vesicoureteric reflux – condition in which damage to internal kidney structures occurs from retrograde urine flow into the kidney; aka. reflux nephropathy, chronic atrophic pyelonephritis, ureteral reflux.
Vesicular – pertaining to or resembling vesicles.
Vesiculation (vesiculated) – formation of vesicles or state of having or forming them.
Viable biomaterials – see biomaterials, viable.
Vimentin – an intermediate filament cytoskeleton attachment protein.
Virion – a single physical virus particle.
Virucide – the destruction of active or dormant virus particles (Section 10.4).
Virus – A parasite (consisting primarily of genetic material enclosed in a protein capsid shell) that invades cells and takes over their molecular machinery in order to copy itself.
Viscera (visceral) – internal organs enclosed within a cavity, especially the abdominal organs.
Viscosity – resistance of a fluid to shearing, when the fluid is in motion (Section 188.8.131.52).
Vitreous carbon – a type of graphite formed by the decomposition of hydrocarbon gases on smooth surfaces (such as glazed porcelain) at temperatures above 650 oC (Section 184.108.40.206); aka. polymeric carbon, glassy carbon.
Vitreous humor – in anatomy, a delicate network enclosing in its meshes a clear watery fluid filling the interior of the eyeball behind the lens.
Volumetric – pertaining to geometric volume of an object.
Volvulus – a twisting of the bowel upon itself, causing obstruction.
Vroman effect – the temporal succession of molecular species adherent to surfaces of implants ; named after its discoverer, Leo Vroman.
Waldenstrom’s macroglobulinemia – excessive number of plasma cells, which are responsible for IgM globulin synthesis.
Warfarin – an anticoagulant drug.
WBC – white blood cell; see leukocyte.
White blood cell (WBC) – see leukocyte.
Whorl – spiral arrangement of cardiac muscular fibers.
Xenogeneic – derived from nonhuman tissues or cells
Young’s modulus – in mechanical engineering, a modulus relating tensile (or compressive) stress to strain in a rod that is free to contract or expand transversely. The relevant measure of strain is the elongation divided by the initial length (see also strain and stress).
Zeiosis – the violent plasma membrane blebbing of a dying cell.
Zeta potential – the overall charge a particle acquires in a specific medium; the magnitude of the zeta potential gives an indication of the potential stability of a colloidal system of these particles.
Zonula occludens – tight junction between columnar epithelial
Zymogenic – pertaining to a substance (a zymogen or proenzyme) that develops into an enzyme capable of producing or causing fermentation or digestion (e.g. pepsinogen, trypsinogen); a cell that produces zymogens (proenzymes).
Zymosan – An insoluble carbohydrate derived from yeast cell walls, used especially in the immunoassay of properdin (a serum protein that helps destroy bacteria and viruses).
Last updated on 30 April 2004