Dictionary

nevus A pigmented spot on the skin, such as a mole. The plural of nevus is nevi.

neutrophilia Too many neutrophils in the blood. Neutrophilia may be due merely to a shift of neutrophils into the circulating blood as occurs, for example, with vigorous exercise and with cortisone medications. A true increase in neutrophil production often reflects infection, particularly bacterial infection. See also neutrophil; neutropenia.

neutrophil A type of white blood cell, a granulocyte that is filled with microscopic granules, little sacs containing enzymes that digest microorganisms. Also known as polymorphonuclear leukocyte or poly.

neutropenia A marked decrease in the number of neutrophils, neutrophils being a type of white blood cell (specifically a form of granulocyte) filled with neutrally-staining granules, tiny sacs of enzymes that help the cell to kill and digest microorganisms it has engulfed by phagocytosis. The mature neutrophil has a segmented nucleus (it is called a…

neurotransmitter A chemical that is released from a nerve cell which thereby transmits an impulse from a nerve cell to another nerve, muscle, organ, or other tissue. A neurotransmitter is a messenger of neurologic information from one cell to another.

neurotoxin Any substance that is capable of causing damage to nerves or nerve tissue. For example, arsenic and lead are neurotoxins.

neurotoxic Poisonous to nerves or nerve tissue.

neurosyphilis, tabes The slowly progressive degeneration of the spinal cord that occurs in the tertiary phase of syphilis, a decade or more after a person contracts the infection. Among the features of tabes neurosyphilis are sharp, lightning-like pain; wobbliness (ataxia); deterioration of the optic nerve, leading to blindness; urinary incontinence; loss of the sense of…

neurosyphilis Neurological complications in the third (tertiary) and final phase of syphilis, which involve the central nervous system and can include psychosis, pain, and loss of physical control over a variety of bodily functions. See also syphilis.

neurosurgeon A physician who specializes in surgery on the brain and other parts of the nervous system.

neuropsychologist A psychologist who has completed special training in the neurobiological causes of brain disorders and who specializes in diagnosing and treating these illnesses by using a predominantly medical (as opposed to psychoanalytical) approach.

neuropathy, hypoglossal See hypoglossal neuropathy.