Porth's Essentials of Pathophysiology, 4e

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Glossary

Mutagen  Any chemical or physical agent that induces a genetic mutation (an unusual change in form, quality, or some other characteristic) or increases the mutation rate by causing changes in DNA. Mydriasis  Physiologic dilatation of the pupil of the eye. Myoclonus  A spasm of a portion of a muscle, an entire muscle, or a group of muscles. Myoglobin  The oxygen-transporting pigment of muscle consisting of one heme molecule containing one iron molecule attached to a single globin chain. Myopathy  Any disease or abnormal condition of skel- etal muscle, usually characterized by muscle weak- ness, wasting, and histologic changes within muscle tissue. Myotome  The muscle plate or portion of an embry- onic somite that develops into a voluntary muscle; or a group of muscles innervated by a single spinal segment. Necrosis  Localized tissue death that occurs in groups of cells or part of a structure or an organ in response to disease or injury. Neutropenia  An abnormal decrease in the number of neutrophilic leukocytes in the blood. Nidus  The point where a morbid process originates, develops, or is located. Nociception  The reception of painful stimuli from the physical or mechanical injury to body tissues by nociceptors (receptors usually found in either the skin or the walls of the viscera). Nosocomial  Pertaining to or originating in a hospital, such as a nosocomial infection; an infection acquired during hospitalization. Nystagmus  Involuntary, rapid, rhythmic movements of the eyeball. Oncogene  A gene that is capable of causing the initial and continuing conversion of normal cells into cancer cells. Oncotic  Relating to, caused by, or marked by edema or any swelling. Oocyte  A primordial or incompletely developed ovum. Oogenesis  The process of the growth and maturation of the female gametes, or ova. Opacification  An act or process of becoming or ren- dering impenetrable to light rays, x-rays, or other electromagnetic radiations. Opsonization  The process of making cells, such as bac- teria, more susceptible to the action of phagocytes. Organelle  Any one of the various membrane-bound particles of distinctive morphology and function present within most cells, such as the mitochondria, Golgi complex, and lysosomes. Orthopnea  An abnormal condition in which a person must be in an upright position in order to breathe deeply or comfortably. Orthosis  An external orthopedic appliance or appa- ratus, as a brace or splint, used to support, align, prevent, or correct deformities, or to improve the function of movable parts of the body. Osmolality  The concentration of osmotically active particles in solution expressed in osmols or millios- mols per kilogram of solvent.

Osmolarity  The concentration of osmotically active particles in solution expressed in osmols or millios- mols per liter of solution. Osmosis  The movement or passage of a pure solvent, such as water, through a semipermeable membrane from a solution that has a lower solute concentra- tion to one that has a higher solute concentration. Osteophyte  A bony project or outgrowth. Palpable  Perceptible by touch. Pandemic  A sudden outbreak, or epidemic, of a disease occurring over a widespread geographic area and affecting a high proportion of the population. Papilla  A small, nipple-shaped projection, elevation, or structure, such as the conoid papillae of the tongue. Papule  A small, circumscribed, solid elevation of the skin less than one centimeter in diameter. (Adjective: papular) Paracrine  A mode of hormone action in which a chemical messenger that is synthesized and released from a cell acts on nearby cells of a different type and affects their function. Paralysis  An abnormal condition characterized by the impairment or loss of motor function due to a lesion of the neural or muscular mechanism. Paraneoplastic  Relating to alterations produced in tissue remote from a tumor or its metastases. Parenchyma  The basic tissue or elements of an organ as distinguished from supporting or connective tissue or elements. (Adjective: parenchymal) Paresis  Slight or partial paralysis. Paresthesia  Any abnormal touch sensation, which can be experienced as numbness, tingling, or a “pins and needles” feeling, often in the absence of external stimuli. Parietal  Pertaining to the outer wall of a cavity or organ; or pertaining to the parietal bone of the skull or the parietal lobe of the brain. Parous  Having borne one or more viable offspring. Pathogen  Any microorganism capable of producing disease. Pedigree  A systematic presentation, such as in a table, chart, or list, of an individual’s ancestors that is used in human genetics in the analysis of inheritance. Peptide  Any of a class of molecular chain compounds composed of two or more amino acids joined by peptide bonds. Perfusion  The process or act of pouring over or through, especially the passage of a fluid through a specific organ or an area of the body. Peripheral  Pertaining to the outside, surface, or sur- rounding area of an organ or other structure; or located away from a center or central structure. Permeable  A condition of being pervious, or per- mitting passage, so that fluids and certain other substances can pass through, as in a permeable membrane. Pervasive  Pertaining to something that becomes diffused throughout every part. Petechia  A tiny, perfectly round, purplish-red spot that appears on the skin as a result of minute intradermal or submucous hemorrhage. (Plural: petechiae)