Medical Dictionary: Glossary (M)

What is macrobiota?

The living organisms of a region that are large enough to be seen with the naked eye.

What is macrolide?

A class of antibiotics that includes Biaxin, Clarithromycin and Erythromycin.

What is macrophage?

A type of white blood cell that ingests foreign material. Macrophages are key players in the immune response to foreign invaders of the body, such as infectious microorgansims.

What is malaria?

An infectious disease caused by protozoan parasites from the Plasmodium family that can be transmitted by the bite of the Anopheles mosquito or by a contaminated needle or transfusion.

What is malnutrition?

A term used to refer to any condition in which the body does not receive enough nutrients for proper function.

What is mast cell?

A granulocyte found in connective tissue whose normal function is unknown but that is frequently injured during allergic reactions. When a mast cell is injured, it releases strong chemicals, including histamine, into the tissues and blood.

What is measles?

An acute and highly contagious viral disease characterized by fever, runny nose, cough, red eyes, and a spreading skin rash.

What is melatonin?

A hormone that is produced by the pineal gland and is closely involved in regulating the sleeping and waking cycles.

What is metabolic?

The biochemical processes that occur within living organisms. Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances).