Medications

Piss: A vulgar but ancient word used both as a noun and verb: 1. (noun) Urine. 2. (verb) To urinate. Piss is descended from the Middle English pisse, from the Old French pissier, from the Latin pisiare. Last Editorial Review: 11/11/2004 Urine:...

Pisa syndrome - Medical

Pisa syndrome: A condition in which there is sustained involuntary flexion of the body and head to one side and slight rotation of the trunk so the person appears to lean like the Leaning Tower of Pisa. The Pisa syndrome is an adverse effect (a sid...

Piriformis syndrome - Medical

Piriformis syndrome: Irritation of the sciatic nerve caused by compression of the nerve within the buttock by the piriformis muscle. Typically, the pain of the piriformis syndrome is increased by contraction of the piriformis muscle, prolonged sitti...

Piriformis muscle - Medical

Piriformis muscle: A muscle that begins at the front surface of the sacrum (the V-shaped bone between the buttocks at the base of the spine) and passes through the greater sciatic notch to attach to the top of the thigh bone (femur) at its bony promi...

Piperine - Medical

Piperine: A pungent alkaloid that is concentrated in the outer skin of pepper berries (which gives pepper much of its bite) and is found in other spices and vegetables including jalapeno peppers. Piperine is used as a flavoring and as an insecticide....

Pinworm infection - Medical

Pinworm infection: An infection caused by a small, white intestinal worm: the pinworm or, more formally, Enterobius vermicularis. The pinworm is about the length of a staple and lives for the most part within the rectum of humans. While an infected p...

Pinosome - Medical

Pinosome: A tiny fluid-filled vesicle (bubble) within a cell. Pinosomes are created in the process of pinocytosis in which tiny incuppings called caveolae (little caves) in the surface of the cell close and then pinch off to form pinosomes within th...

Pinocytosis - Medical

Pinocytosis: A cellular process that permits the active transport of fluid from outside the cell through the membrane surrounding the cell into the inside of the cell. In pinocytosis, tiny incuppings called caveolae (little caves) in the surface of...

Pinnate - Medical

Pinnate: 1. Like the pinna, the part of the ear that projects ("wings out") from the head. 2. Like a feather or leaf with similar parts arranged symmetrically on opposite sides of a central axis. From the Latin pinnatus meaning winged or feathere...

Pinna - Medical

Pinna: The ear or, to be more precise, the part of the ear that projects like a little wing from the head. In Latin, pinna means wing. Last Editorial Review: 4/27/2011 5:27:15 PM...

Pinkeye - Medical

Pinkeye: Also called conjunctivitis. Redness or irritation of the conjunctivae, the membranes on the inner part of the eyelids and the membranes covering the whites of the eyes. These membranes react to a wide range of bacteria, viruses, allergy-prov...

PINK1 - Medical

PINK1: Abbreviation for PTEN-induced kinase 1. (Kinases are key regulators of cell function that catalyze the addition of a negatively charged phosphate group to a protein. This process of protein phosphorylation, in turn, regulates protein function ...

Pinguicula - Medical

Pinguicula: Alternate spelling of pinguecula. Irrespective of spelling, the accent is on the second syllable which is pronounced gwek.Last Editorial Review: 4/27/2011 5:27:15 PM...

Pinguecula - Medical

Pinguecula: A yellow spot on the white of the eye, usually toward the inside (nose side) of the eye, associated with aging. It looks fatty (in Latin the word pinguiculus means fattish), and is due to an accumulation of connective tissue.Last Edito...

Pineocytoma - Medical

Pineocytoma: An uncommon slow-growing tumor of the pineal gland. Symptoms include hydrocephalus, paralysis of upward gaze, gait disturbances, and precocious puberty. Also known as a pinealocytoma or pinealoma. Last Editorial Review: 4/27/2011 ...

Pineoblastoma - Medical

Pineoblastoma: A fast-growing brain tumor in the pineal gland that originates in germ cells. Also known as a pineal teratoma.Last Editorial Review: 4/27/2011 5:27:15 PM...

Pinel system - Medical

Pinel system: The policy of treating the mentally ill in hospitals and other institutions humanely and without the use of forcible restraints of any type. Named for the great French psychiatrist, Philippe Pinel (1745-1826), who was named director ...

Pinealoma - Medical

Pinealoma: An uncommon slow-growing tumor of the pineal gland. Symptoms include hydrocephalus, paralysis of upward gaze, gait disturbances, and precocious puberty. Also known as a pinealocytoma or pineocytoma. Last Editorial Review: 4/27/2011 5:27:1...

Pineal region tumor - Medical

Pineal region tumor: A brain tumor on or near the pineal gland. There are at least 17 types of pineal gland tumors, most of which are not cancerous but can nonetheless cause extreme distress. They account for about 1 percent of brain tumors in ...

Pineal gland - Medical

Pineal gland: A small gland located deep within in the brain. It is believed to secrete melatonin, and may therefore be part of the body's sleep-regulation apparatus.Last Editorial Review: 4/27/2011 5:27:15 PM...

Pinched nerve - Medical

Pinched nerve: See: Nerve compression.Last Editorial Review: 10/16/2004 Medical Author: Jason C. Eck, DO, MS Jason C. Eck, DO, MS Dr. Eck received a ...

Pin1 - Medical

Pin1: An enzyme that permits brain cells to function normally. Pin1 may also protect against Alzheimer's disease. The enzyme is clearly involved in regulating mitosis (cell division). The Pin1 level in the brains of Alzheimer patients is greatly redu...

Pimply - Medical

Pimply: Having pimples. Papuliferous and papilliferous are fancy words for what is simply pimply.Last Editorial Review: 6/16/2004 Pimples: Small papules or pustules. See: Pimple.Last Editorial Review: 6/16/2004 Papuliferous: 1. Having papules. 2....

Pimples - Medical

Pimples: Small papules or pustules. See: Pimple.Last Editorial Review: 6/16/2004 Papule: A small solid rounded bump rising from the skin that is usually less than 1 centimeter in diameter (less than 3/8 inch across). Papules may open when scr...

Pimple - Medical

Pimple: A small papule or pustule. Pimples are sebaceous glands (oil glands) that are infected with bacteria, become inflamed, and fill with pus. Pimples are due to overactivity of the sebaceous glands located at the base of the hair follicles, espec...

Pimecrolimus - Medical

Pimecrolimus: A chemical used to treat atopic dermatitis (eczema). Pimecrolimus prevents the activation of T cells by blocking the effects of chemicals called cytokines that stimulate T-cells. Pimecrolimus also reduces the ability of mast cells to re...

Pilonidal sinus - Medical

Pilonidal sinus: A sinus tract from which there may be chronic drainage of pus, due to an embedded tuft of hair, most often in the crease between the buttocks, but can occur elsewhere in the body, as between the fingers in barbers, hairdressers, and...

Pilonidal cyst - Medical

Pilonidal cyst: A special kind of abscess that occurs in the cleft between the buttocks. Forms frequently in adolescence after long trips that involve sitting. The word "pilonidal" is derived from the Latin words pilus (meaning hair) and nidus (mean...

Pilonidal - Medical

Pilonidal: Refers to an embedded (ingrown) hair or tuft of hair. Literally, a nest of hair. From the Latin pilus (meaning hair) and nidus (meaning nest). Last Editorial Review: 3/12/2004...

Piloerection - Medical

Piloerection: Erection of the hair of the skin. Piloerection of the hair, for example, on the arm makes it "stand on end." Piloerection starts when a stimulus such as cold or fright causes a discharge from the ( involuntary) nervous system that t...