Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «P»:
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-provoking
agents, irritants and toxic agents. Viral an...
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. ...
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 feathered, from the Latin pinna meaning a wing or feather....
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 the cell close and then pinch off to form pinosome...
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 the cytoplasm of the cell.
Pinocytosis permits the ac...
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 person is asleep, female pinworms leave the intesti...
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. The word is derived from the Latin piper, pepper....
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 prominence called the greater trochanter. The gluteus ...
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 sitting, or direct pressure applied to the muscle. Butt...
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 side-effect) of some medications. It occurs sometimes ...
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....
Pistol-shot pulse: See: Pulse, water hammer....
Pit, ear: Tiny pit in front of the ear. Also
preauricular pit. A minor anomaly of no great consequence in itself. More common in blacks
than whites and in females than males. Can recur in families. The presence of 2 or more
minor anomalies in a child increases the probability that the child has a ma...
Pitting edema: Observable swelling of body tissues due to fluid
accumulation that may be demonstrated by applying pressure to the swollen area
(such as by depressing the skin with a finger). If the pressing causes an
indentation that persists for some time after the release of the pressure, the
Pituitary: 1. As an adjective, pertaining to the pituitary gland or its hormonal secretions. 2. As a noun, the pituitary gland itself.