Medical terms - Letter P (page 24) | MedicalVocabulary.org

Procollagen

A precursor (forerunner) of collagen, the protein that adds strength and support to many body tissues
Proctitis

Inflammation of the rectum. This may be due to a considerable number of causes, among them infectious agents and ulcerative colitis. Infectious proctitis is often due to agents such as Chlamydia trachomatis, Neisseria…
Proctitis, ulcerative

Ulcerative colitis that is limited to the rectum. Ulcerative colitis itself is a relatively common disease involving inflammation of the large intestine (the colon). The cause is unknown. It is a form of inflammatory…
Proctocele

See: Rectocele
Proctology

A medical specialty that deals with disorders of the rectum and anus
Proctosigmoidoscopy

See: Sigmoidoscopy
Prodrug

A precursor (forerunner) of a drug. A prodrug must undergo chemical conversion by metabolic processes before becoming an active pharmacological agent. For example, sulfasalazine is a prodrug. It is not active in its…
Product, gene

The RNA or protein that results from the expression of a gene. The amount of gene product is a measure of the degree of gene activity.
Progeny

The children and other descendants. For example one might say that the progeny of someone with a genetic (inherited) condition such as Huntington disease are themselves at risk for the disease. The word 'progeny' is the…
Progeria

A rare genetic disorder that causes children to age prematurely. The classic type of childhood progeria is Hutchinson-Gilford syndrome, which is commonly referred to as progeria. It is characterized by dwarfism…
Progestational hormone

A synonym for the hormone progesterone. See: Progesterone
Progesterone

A female hormone and the principal progestational hormone that is made mainly by the corpus luteum in the ovary and by the placenta. Progesterone prepares the lining (endometrium) of the uterus (the womb) to receive and…
Progesterone receptor test

A laboratory test to determine if breast cancer cells have progesterone receptors on their surface. If the cells have progesterone receptors, they may depend on progesterone for growth and will usually respond to…
Progestin

Any one of a group of steroid hormones that have the effect of progesterone
Prognathism

An overly prominent jaw.
Prognosis

1. The expected course of a disease.2. The patient's chance of recovery. The prognosis predicts the outcome of a disease and therefore the future for the patient. His prognosis is grim, for example, while hers is good…
Prognostic

1. (adjective) In medicine, relating to the prognosis of a disease. For example, a favorable prognostic factor.2. (adjective) Generally, relating to a prediction. For example, a prognostic index for the economy. 3…
Prograf

Brand name of tacrolimus. See: Tacrolimus
Programmed cell death

A term often used interchangeably with apoptosis. See: Apoptosis
Progressive

Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse
Progressive cardiomyopathic lentiginosis

See: LEOPARD syndrome
Progressive dementia with cerebellar ataxia

See: Gerstmann-Straussler-Scheinker syndrome
Progressive infantile poliodystrophy

Ers: A progressive disease of the nervous system characterized by spasticity (tightness), myoclonus and dementia and by liver problems with jaundice and cirrhosis. This disorder, first described by Alpers in 1931 as…
Progressive multifocal leukoencephalopathy

A rapidly progressive, often fatal viral infection of the brain. Commonly abbreviated as PML. PML is believed to be due to the Jacob-Creutzfeldt (JC) papovavirus. The virus infects oligodendrocytes (support cells in the…
Progressive supranuclear palsy

Progressive supranuclear palsy: A neurologic disorder of unknown origin that gradually destroys cells in many areas of the brain, leading to serious and permanent problems with the control of gait and balance. The most…
Progressive vaccinia

A severe complication of smallpox vaccination that occurs because of an immune defect in the vaccinated individual or in a susceptible contact of that person. In progressive vaccinia, the primary vaccination site does…
Proinflammatory

Capable of promoting inflammation. For example, air pollution may have proinflammatory effects
Prokaryote

A unicellular organism lacking a nuclear membrane, a discrete nucleus, and other specialized compartments within the cell. Bacteria and viruses are prokaryotes. It appears that life arose on earth about 4 billion years…
Prokaryotic

Pertaining to prokaryotes
Prolactin

A hormone secreted by the pituitary gland. Prolactin stimulates lactation (milk production). It also has many other functions, including essential roles in the maintenance of the immune system. Abnormally high prolactin…
Proliferative

Growing and increasing in number rapidly. For example, the lymphoproliferative disorders are diseases in which there is malignant growth of lymphoid cells and of cells from the reticuloendothelial system (which take up…
Proline

An amino acid, one of the 20 building blocks of protein. A dietary nonessential amino acid, proline is a major constituent of collagen. Symbol: Pro
Prominent vertebra

The 7th cervical (neck) vertebra (C7) is sometimes called the prominent vertebra because of the length of its spinous process (the projection off the back of the vertebral body). The spinous process of the top thoracic…
Prominentia laryngea

The prominence of the larynx, more commonly known as the Adam's apple. This familiar feature in front of the neck is due to forward protrusion of the largest cartilage of the larynx. It takes its name from the story…
PROMM

Proximal myotonic myopathy. See: Myotonic dystrophy type 2
Promoter

In molecular biology, a site on DNA to which the enzyme RNA polymerase can bind and initiate the transcription of DNA into RNA
Pronation

A type of foot that rolls far inward during the weight-bearing phase of the stride. This type of foot is characterized by a very low or flat arch. Heavier people often have feet of this type.
Pronator foot type

A type of foot that rolls far inward during the weight-bearing phase of the stride. This type of foot is characterized by a very low or flat arch. Heavier people often have feet of this type
Prone

The first sulfa drug to be discovered. Largely of historic interest today. The discovery was made by the great German physician and chemist Gerhard Domagk (1895-1964). In 1925 Domagk was named Lecturer in Pathologic…
Prontosil

The first sulfa drug to be discovered. Largely of historic interest today. The discovery was made by the great German physician and chemist Gerhard Domagk (1895-1964). In 1925 Domagk was named Lecturer in Pathologic…
Pronucleus

A cell nucleus with a haploid set of chromosomes (23 chromosomes in humans) resulting from meiosis (germ-cell division). The male pronucleus is the sperm nucleus after it has entered the ovum at fertilization but before…
Prophase chromosome

A chromosome at the prophase stage in the cell cycle, before metaphase (when a chromosome is most highly condensed). The chromosomes in prophase are distended and often tangled like a ball of twine within the nucleus of…
Prophylactic

A preventive measure. The word comes from the Greek for 'an advance guard,' an apt term for a measure taken to fend off a disease or another unwanted consequence. A prophylactic is a medication or a treatment designed…
Prophylactic cranial irradiation

Radiation therapy to the head intended to prevent cancer from spreading (metastasizing) to the brain.
Prophylaxis

A measure taken for the prevention of a disease or condition. For example, dental prophylaxis consists of removing plaque and cleaning the teeth to prevent cavities and gum disease. The word 'prophylaxis' is from the…
Propionibacterium acnes

A ubiquitous skin-dwelling organism that is involved in causing acne.In addition to acne, this bacterium (P. acnes) is associated with corneal ulcers, endocarditis, sarcoidosis, cholesterol gallstones, allergic…
Proportional counter

A device for measuring radioactivity. More technically, a proportional counter counts the emission of radioactive particles which permits the discrimination between particles or rays of different energies
Proposita

A female through whom a family medically comes to light (is first ascertained). Also called the proband or index case. The male counterpart of a proposita is a propositus.
Propositus

A male through whom a family medically comes to light (is first ascertained). Also called the proband or index case. The feminine of propositus is proposita.
Proprioception

The ability to sense stimuli arising within the body. Even if you are blindfolded, you know through proprioception if your arm is above your head or hanging by your side. The word 'proprioception' was coined in 1906 by…