Medical terms - Letter P (page 16) | MedicalVocabulary.org

Plasticity, brain

See Neuroplasticity
Platelet

An irregular, disc-shaped element in the blood that assists in blood clotting. During normal blood clotting, the platelets clump together (aggregate). Although platelets are often classed as blood cells, they are…
Platelet aggregation

The clumping together of platelets in the blood. Platelet aggregation is part of the sequence of events leading to the formation of a thrombus (clot)
Platelet count

The calculated number of platelets in a volume of blood, usually expressed as platelets per cubic millimeter (cmm) of whole blood. Platelets are the smallest cell-like structures in the blood and are important for blood…
Plegia

Suffix meaning paralysis or a stroke. As in cardioplegia (paralysis of the heart), hemiplegia (paralysis of one side of the body), paraplegia (paralysis of the legs), and quadriplegia (paralysis of all four…
Pleiotropic

1. Producing many effects. 2. Multiple effects from a single gene. For example, the Marfan gene is pleiotropic with widespread effects and can cause long fingers and toes (arachnodactyly), dislocation of the lens of the…
Pleiotropic cytokine

Cytokine that affects the activity of multiple cell types. A cytokine is a small protein that has a specific effect on the interactions between cells, on communications between cells, or on the behavior of cells
Pleomorphic

Many-formed. A tumor may be pleomorphic. Pleomorphic is synonymous with protean (capable of assuming different shapes like the many-formed Greek god Proteus).
Pleonasm

An excess in the number of parts or in the size of a growth. Pleonasm comes from a Greek word (pleonasmos) meaning exaggeration or redundancy. A pleonasm in language is also a redundancy. It is the use of more words…
Plethoric

Florid, red-faced.
Pleura

The thin covering that protects and cushions the lungs. The pleura is made up of two layers of tissue that are separated by a small amount of fluid.
Pleurae

Pleural of pleura (the thin covering that protects and cushions the lungs)
Pleural

Pertaining to the pleura, the thin covering that protects the lungs. The term 'pleural' is pronounced like 'plural' (but does not have plural meanings)
Pleural effusion

Excess fluid between the two membranes that envelop the lungs. These membranes are called the visceral and parietal pleurae. The visceral pleura wraps around the lung while the parietal pleura lines the inner chest…
Pleural effusion, fetal

See: Fetal pleural effusion
Pleural space

The tiny area between the two layers of the pleura (the thin covering that protects and cushions the lungs). The pleural space is normally filled with a small amount of fluid
Pleurisy

Pleurisy: Inflammation of the pleura, the linings surrounding the lungs. There are two layers of pleura; one covering the lung and the other covering the inner wall of the chest. These two layers are lubricated by…
Pleuritis

Inflammation of the pleura. When the pleura becomes inflamed, it can produce more than the normal amount of fluid, causing a pleural effusion
Pleurodesis

A procedure that causes the membranes around the lung to stick together and prevents the buildup of fluid in the space between the membranes. This procedure is done in cases of severe recurrent pleural effusion (fluid…
Pleurodynia

Also known as Bornholm disease, this is a temporary illness that is a result of virus infection. The disease features fever and intense abdominal and chest pains with headache. The chest pain is typically worsened by…
Plexus

1. In medicine, a network or tangle of lymphatic vessels, nerves, or veins. For example, the brachial plexus is a network of nerves leading to the arm. 2. In general, any interwoven entity made up of elements in a…
Plexus, brachial

See: Brachial plexus
PLGF

Placental growth factor
Plodia interpunctella

See: Meal moth
PLP

See: Proteolipid protein
PLP1

The gene encoding proteolipid protein, or lipophilin, the primary constituent of myelin. The PLP1 gene is on the X chromosome in band Xq22. Mutations in PLP1 cause Pelizaeus-Merzbacher disease (PMD) and X-linked spastic…
Plumbism

Another name for lead poisoning.
Plummer's disease

Toxic multinodular goiter. Also called Parry's disease
Plummer-Vinson syndrome

Iron deficiency anemia, esophageal webs, and dysphagia (difficulty swallowing). The iron deficiency is typically chronic and severe. It triggers the growth of web-like membranes in the throat which cause dysphagia. The…
Plyometrics

Any exercise in which muscles are repeatedly and rapidly stretched ('loaded') and then contracted (as in jumping high off the ground or in push-ups with a clap between them). The aim of plyometrics is to improve muscle…
PMD

Pelizaeus-Merzbacher disease
PML

Stands for 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…
PMLD

Pelizaeus-Merzbacher-like disease
PMR (Polymyalgia Rheumatica)

Polymyalgia Rheumatica: A disorder of the muscles and joints of older persons characterized by pain and stiffness, affecting both sides of the body, and involving the shoulders, arms, neck, and buttock areas.
PMS (PreMenstrual Syndrome)

See Premenstrual syndrome
PNET

Primitive neuroectodermal tumor. One of a remarkable group of tumors that originate in cells from the primitive neural crest and share the same reciprocal translocation between chromosomes 11 and 22 and the same…
Pneuma

The life-giving principle. According to the school of medicine in ancient Alexandria, life was associated with a vapor called the pneuma. The belief in pneuma was called pneumatism. In hindsight, pneumatism was an early…
Pneumatic larynx

A device that uses air to produce sound, helping a person whose larynx has been removed to talk
Pneumatism

See: Pneuma
Pneumo-

Prefix pertaining to breathing, respiration, the lungs, pneumonia, or air
Pneumococcal immunization

Vaccination to help prevent infection by Streptococcus pneumoniae, also known as the pneumococcus bacterium. This bacterium causes one of the most common and severe forms of pneumonia. To prevent this form of pneumonia…
Pneumococcus (Streptococcus pneumoniae)

A type of bacterium that comes in pairs and is shaped like a lancet (a surgical knife with a short wide two-edged blade). Pneumococcus is the leading cause of bacterial pneumonia and otitis media (middle ear infections)…
Pneumoconiosis

The deposition of particulate matter such as asbestos and silicon in the lungs. See also: Black lung disease
Pneumoconiosis, coal miner's

See: Black lung disease
Pneumocystis

Pneumocystis jiroveci (previously classified as Pneumocystis carinii), the fungus that causes pneumocystis pneumonia (PCP). Pneumocystis jiroveci is found worldwide, in humans and animals. Serologic evidence indicates…
Pneumocystis carinii

Now called Pneumocystis jiroveci. See: Pneumocystis
Pneumocystis jiroveci

See: Pneumocystis
Pneumocystis pneumonia

One of the cells lining the alveoli (the air sacs) in the lung. The alveoli are, in fact, lined with two types of cells termed the type 1 and type 2 pneumocytes: Type 1 pneumocyte: The cell responsible for the gas…
Pneumocyte

One of the cells lining the alveoli (the air sacs) in the lung. The alveoli are, in fact, lined with two types of cells termed the type 1 and type 2 pneumocytes: > >Type 1 pneumocyte: The cell responsible for the gas…
Pneumomediastinum

Free air in the mediastinum (space betweens the lungs) which may give rise to pneumothorax or pneumopericardium and compromise the lungs or heart.