Porth's Essentials of Pathophysiology, 4e

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Glossary

Phagocytosis  The process by which certain cells engulf and consume foreign material and cell debris. Phalanx  Any one of the bones composing the fingers of each hand and the toes of each foot. Phenotype  The complete physical, biochemical, and physiologic makeup of an individual, as determined by the interaction of both genetic makeup and envi- ronmental factors. Pheresis  A procedure in which blood is withdrawn from a donor, a portion (plasma, leukocytes, etc.) is separated and retained, and the remainder is reper- fused into the donor. It includes plasmapheresis and leukophoresis. Pili  Hair; or in microbiology, the minute filamentous appendages of certain bacteria. (Singular: pilus) Plethora  A body condition characterized by an excess of any of the body fluids, especially blood, marked by distention and a beefy red coloration. (Adjective: plethoric) Plexus  A network of intersecting nerves, blood vessels, or lymphatic vessels. Polygene  Any of a group of nonallelic genes that inter- act to influence the same character in the same way so that the effect is cumulative, usually of a quanti- tative nature, as size, weight, or skin pigmentation. (Adjective: polygenic) Polymorph  One of several, or many, forms of an organism or cell. (Adjective: polymorphic) Polyp  A small, tumor-like growth that protrudes from a mucous membrane surface. Polypeptide  A molecular chain of more than two amino acids joined by peptide bonds. Presbyopia  A visual condition (farsightedness) that commonly develops with advancing years or old age in which the lens loses elasticity, causing defective accommodation and inability to focus sharply for near vision. Prevalence  The number of new and old cases of a disease that are present in a population at a given time, or occurrences of an event during a particular period of time. Prodrome  An early symptom indicating the onset of a condition or disease. (Adjective: prodromal) Prokaryotic  Pertaining to an organism, such as bacte- rium, with cells lacking a true nucleus and nuclear membrane that reproduces through simple fission. Prolapse  The falling down, sinking, or sliding of an organ from its normal position or location in the body. Proliferation  The reproduction or multiplication of similar forms, especially cells. Pronation  Assumption of a position in which the ven- tral, or front, surface of the body or part of the body faces downward. (Adjective: prone) Propagation  The act or action of reproduction. Proprioception  The reception of stimuli originating from within the body regarding body position and muscular activity by proprioceptors (sensory nerve endings found in muscles, tendons, joints). Prosthesis  An artificial replacement for a missing body part; or a device designed and applied to improve function, such as a hearing aid.

Proteoglycans  Any one of a group of polysaccharide- protein conjugates occurring primarily in the matrix of connective tissue and cartilage. Proto-oncogene  A normal cellular gene that with altera- tion, such as by mutation, becomes an active oncogene. Proximal  Closer to a point of reference, usually the trunk of the body, than other parts of the body. Pruritus  The symptom of itching, an uncomfortable sensation leading to the urge to rub or scratch the skin to obtain relief. (Adjective: pruritic) Purpura  A small hemorrhage, up to about 1 cm in diameter, in the skin, mucous membrane, or serosal surface; or any of several bleeding disorders charac- terized by the presence of purpuric lesions. Purulent  Producing or containing pus. Quiescent  Quiet, causing no disturbance, activity, or symptoms. Reflux  An abnormal backward or return flow of a fluid, such as stomach contents, blood, or urine. Regurgitation  A flow of material that is in the opposite direction from normal, as in the return of swallowed food into the mouth or the backward flow of blood through a defective heart valve. Remission  The partial or complete disappearance of the symptoms of a chronic or malignant disease; or the period of time during which the abatement of symptoms occurs. Resorption  The loss of substance or bone by physi- ologic or pathologic means; for example, the loss of dentin and cementum of a tooth. Retrograde  Moving backward or against the usual direction of flow; reverting to an earlier state or worse condition (degenerating); catabolic. Retroversion  A condition in which an entire organ is tipped backward or in a posterior direction, usually without flexion or other distortion. Rhabdomyolysis  Destruction or degeneration of muscle, associated with myoglobinuria (excretion of myoglobin in the urine). Rostral  Situated near a beak (oral or nasal region). Sacroiliitis  Inflammation in the sacroiliac joint. Saprophyte  An organism that obtains nourishment from the products of organic breakdown and decay. (Adjective: saprophytic) Sclerosis  A condition characterized by induration or hardening of tissue resulting from any of several causes, including inflammation, diseases of the inter- stitial substance, and increased formation of connec- tive tissues. Scotopic vision  Describes vision, especially night vision, when the eye is dark adapted. Semipermeable  Partially but not wholly permeable, especially a membrane that permits the passage of some (usually small) molecules but not the passage of other (usually larger) particles. Senescence  The process or condition of aging or grow- ing old. Sepsis  The presence in the blood or other tissues of pathogenic microorganisms or their toxins; or the condition resulting from the spread of microorgan- isms or their products. (Adjective: septic)