Medical terms - Letter P (page 14) | MedicalVocabulary.org

Pigmentation

The coloring of the skin, hair, mucous membranes, and retina of the eye. Pigmentation is due to the deposition of melanin which is a coloring matter. The melanin is produced by specialized cells called melanocytes…
Pigmented villonodular synovitis

A benign proliferative form of monoarthritis (arthritis in just one joint) that can occurs at any age but is most common in adults age 20-50. The joint most often affected is the knee with the hip, ankle, and shoulder…
Piles

1. A term in use since the 15th century for hemorrhoids. 2. A street name for crack cocaine
Pill

In pharmacy, a medicinal substance in a small round or oval mass meant to be swallowed. Pills often contain a filler and a plastic substance such as lactose that permits the pill to be rolled by hand or machine into the…
Pill splitter

A device for tablet splitting
Pill splitting

See: Tablet splitting
Pill, the

Commonly called 'the pill,' combined oral contraceptives are the most commonly used form of reversible birth control in the United States. This form of birth control suppresses ovulation (the monthly release of an egg…
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…
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)
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)…
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…
Pimecrolimus

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…
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…
Pimples

Small papules or pustules. See: Pimple
Pimply

Having pimples. Papuliferous and papilliferous are fancy words for what is simply pimply
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…
Pinched nerve

See: Nerve compression
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
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…
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
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…
Pineoblastoma

A fast-growing brain tumor in the pineal gland that originates in germ cells. Also known as a pineal teratoma
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
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…
Pinguicula

Alternate spelling of pinguecula. Irrespective of spelling, the accent is on the second syllable which is pronounced gwek
PINK1

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…
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…
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…
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)…
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…
Pinworm infection

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…
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…
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…
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…
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…
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…
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…
Pituitary

1. As an adjective, pertaining to the pituitary gland or its hormonal secretions. 2. As a noun, the pituitary gland itself.
Pituitary adenoma

A benign tumor of the pituitary, the master gland that controls other glands and influences numerous body functions including growth. Although the tumor itself is not cancerous, it may affect pituitary function, and…
Pituitary dwarfism

Dwarfism caused by a lack of growth hormone, usually due to malfunction of the pituitary gland. Children with growth hormone deficiency may grow normally for the first two to three years of life but they then fall…
Pituitary gigantism

Excessive growth and too much height due to chronic overactivity of the pituitary gland which is located at the base of the brain. (Growth hormone is specifically made by the anterior pituitary gland.) In pituitary…
Pituitary gland

The main endocrine gland. It is a small structure in the head. It is called the master gland because it produces hormones that control other glands and many body functions including growth. The pituitary consists of the…
Pituitary, anterior

The front portion of the pituitary, a small gland in the head called the master gland. Hormones secreted by the anterior pituitary influence growth, sexual development, skin pigmentation, thyroid function, and…
Pituitary, posterior

A mild form of eczema that occurs in young children and adolescents and produces mild patchy lightening and slight scaling of the skin of the face (particularly over the cheeks and around the mouth), the shoulders, or…
Pityriasis alba

A common mild rash of unknown origin that can appear on a person of any age (most commonly at 10-35 years of age), may last from several weeks to several months, often begins with a "herald" patch, a large single pink…
Pityriasis rosea

Peutz-Jeghers syndrome.
PJS

Polycystic kidney disease.