Medical terms - Letter M (page 11) | MedicalVocabulary.org

Meralgia paresthetica

Meralgia paresthetica: Entrapment or pinching of the nerve that supplies sensation to the outer portion of the thigh. The lateral femoral cutaneous nerve becomes entrapped as it passes under the ligament of the groin…
Mercaptopurine

A drug that acts as an antimetabolite, interfering with the metabolism of purine bases and inhibiting the synthesis of DNA and RNA. Mercaptopurine is used to treat acute lymphoblastic leukemia, acute myeloid leukemia…
Mercury gilding

A perilous process for gold-plating in which an amalgam of mercury and gold is applied to an object and then exposed to heat to vaporize the mercury and leave the gold behind in a thin layer. The risk is mercury…
Mercury poisoning

The metallic element mercury is poisonous to humans. Mercury poisoning can occur in both acute and chronic forms. Acute mercury poisoning (which today is less common) is associated with ulcerations of the stomach and…
Merkel cell carcinoma

Carcinoma: An infrequent but highly malignant type of skin cancer. Characteristically starts in a sun-exposed area (of the head, neck, arms or legs) in whites 60-80 years of age as a firm, painless, shiny lump that can…
Merkle cell carcinoma

A rapidly growing type of skin cancer, correctly termed Merkel cell carcinoma, after the German anatomist and pathologist Friedrich Sigmund Merkel (1845-1919)
Mesenteric artery

One of the arteries which arises from the abdominal portion of the aorta and distributes blood to most of the intestines
Mesenteric vein

One of the large veins which return blood from the intestines. The inferior (lower) mesenteric vein empties into the splenic vein. The superior (upper) mesenteric vein then joins the splenic vein to create the portal…
Mesentery

A fold of tissue which attaches organs to the body wall. The word mesentery usually refers to the small bowel mesentery which anchors the small intestine to the back of the abdominal wall. Blood vessels, nerves, and…
Mesial

1. Toward the middle. As, for example, a mesial temporal lobe structure.2. In dentistry, toward the middle of the front of the jaw
Mesmerism

1. Originally, a system of therapeutics propounded by Mesmer.2. A precursor of hypnotism, believed by Mesmer to involve animal magnetism.3. By extension, the power to fascinate in a way that is almost hypnotic.The term…
Mesoderm

One of the three primary germ cell layers -- the other two are the ectoderm and endoderm -- in the very early embryo. The mesoderm is the middle layer. It differentiates to gives rise to a number of tissues and…
Mesodermal

Pertaining to the mesoderm or to tissues derived from the mesoderm
Mesothelin

A protein attached to the cell surface that is thought to have a role in cell-adhesion and possibly in cell-to-cell recognition and signalling. Mesothelin is so named because it is made by mesothelial cells. A…
Mesothelioma

Mesothelioma: A malignant tumor of the mesothelium. The mesothelium is the thin lining on the surface of the body cavities and the organs that are contained within them. Most mesotheliomas begin as one or more nodules…
Messenger RNA

The key intermediary in gene expression, translating the DNA's genetic code into the amino acids that make up proteins. Messenger RNA is abbreviated mRNA
Met

Methionine. See also: Amino acid symbols
Metabolic

Relating to metabolism, the whole range of biochemical processes that occur within us (or any living organism). Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances)…
Metabolic diseases, inherited

Also called inborn errors of metabolism, these are heritable (genetic) disorders of biochemistry. Examples include albinism, cystinuria (a cause of kidney stones), phenylketonuria (PKU), and some forms of gout, sun…
Metabolic rate, basal

A measure of the rate of metabolism. For example, someone with an overly active thyroid will have an elevated basal metabolic rate
Metabolic syndrome

Metabolic syndrome: A constellation of conditions that place people at high risk for coronary artery disease. These conditions include type 2 diabetes, obesity, high blood pressure, and a poor lipid profile with…
Metabolism

The whole range of biochemical processes that occur within us (or any living organism). Metabolism consists both of anabolism and catabolism (the buildup and breakdown of substances, respectively). The term is commonly…
Metabolism, inborn error of

A heritable disorder of the biochemistry of the4 body. Examples of inborn errors of metabolism include albinism, cystinuria (a cause of kidney stones), phenylketonuria (PKU), and some forms of gout, sun sensitivity, and…
Metabolomics

The global analysis of metabolites, small molecules generated in the process of metabolism. See also: Metabonomics
Metabonomics

The study of metabolic responses to drugs, environmental changes and diseases. Metabonomics is an extension of genomics (concerned with DNA) and proteomics (concerned with proteins). Following on the heels of genomics…
Metacarpals

Five cylindrical bones extending from the wrist to the fingers.
Metacentric chromosome

A chromosome with arms of equal length.
Metagene

A pattern of gene expression. Not an actual gene. 'We identified aggregate patterns of gene expression (metagenes) that associate with lymph node status and recurrence, and that are capable of predicting outcomes in…
Metallomembrane endopeptidase

(MME) A molecule that is also known as CALLA (common acute lymphocytic leukemia antigen), a cell surface marker for the most common form of acute lymphocytic leukemia (ALL). CALLA is also present on normal tissues and…
Metanalysis

A technique currently popular in medical research, whereby all data from all available studies of something are combined, at times regardless of the quality of the data. The technique is used by researchers to get a…
Metaphase (cell cycle)

The stage in the cell cycle (the sequence of events in the life of a cell) when a chromosome is most highly condensed (and stains most darkly in the laboratory) and so is easiest to distinguish and to study. Metaphase…
Metaphase chromosome

A chromosome in the stage of the cell cycle (the sequence of events in the life of a cell) when a chromosome is most condensed and easiest to distinguish and so to study. Metaphase chromosomes are often chosen for…
Metaphyseal chondrodysplasia (McKusick type)

See: Cartilage hair hypoplasia syndrome
Metapneumovirus

See: Human metapneumovirus
Metapneumovirus, human

See: Human metapneumovirus
Metastasis

1. The process by which cancer spreads from the place at which it first arose as a primary tumor to distant locations in the body.2. The cancer resulting from the spread of the primary tumor. For example, someone with…
Metastasize

The spread from one part of the body to another. When cancer cells metastasize and cause secondary tumors, the cells in the metastatic tumor are like those in the original cancer.
Metatarsal

One of the five cylindrical bones extending from the heel (the tarsus) to the toes on each foot. The metatarsals are numbered from the inside out, so the first metatarsal extends to the big toe and the fifth metatarsal…
Metatarsals

Five cylindrical bones extending from the heel (the tarsus) to the toes. The metatarsals are numbered from the inside out, so the first metatarsal extends to the big toe
Metatarsophalangeal

Referring to both the metatarsus and the phalanges of the toes
Metatarsophalangeal joint sprain

An injury to the big toe due to forced hyperextension (bending back) of the toe. The damage is to the capsule of the first metatarsophalangeal joint and to the ligaments that connect the big toe to the foot. The big toe…
Metatarsus

The part of the foot that lies just beyond the tarsus, between the tarsus and the toes. The skeleton of the metatarsus consists of five long bones termed the metatarsals that extend from the tarsus to the phalanges…
Meter, peak-flow

This hand-held device measures air flow (how fast air is blown out of the lungs). Patients can use peak-flow meters to measure their own air flow regularly. The use of a peak-flow meter allows patients to obtain a much…
Meter, pH

See: pH meter
Metered dose inhaler

See: Metered-dose inhaler
Metered-dose inhaler

Abbreviated MDI. A device that delivers a measured amount of medication as a mist the patient can inhale. A MDI consists of a pressurized canister of medication in a case with a mouthpiece. MDIs are portable, efficient…
Methadone

A synthetic opiate. The most common medical use for methadone is as a legal substitute for heroin in treatment programs for drug addiction. It is usually administered to participating addicts daily in the form of a…
Methadone treatment program

A program for opiate addicts, usually conducted in an outpatient setting. These programs use a long-acting synthetic opiate medication, usually methadone or LAAM, administered orally for a sustained period at a dosage…
Methanococcus jannaschii

A microbe that produces methane, an important energy source, and contains enzymes that withstand high temperatures and pressures. The genome of Methanococcus jannaschii has been completely sequenced
Methemoglobin

A particular type of hemoglobin that is altered so that it is useless for carrying oxygen and delivering it to tissues throughout the human body. Since hemoglobin is the key carrier of oxygen in the blood, its wholesale…