| MRBF | mean renal blood flow |
|---|---|
| MRD | maximum rate of depolarization; measles-rindenpest-distemper [virus group]; medical records departme... |
| MRF | Markov random field; medical record file; melanocyte-[stimulating hormone]-releasing factor; mesence... |
| MRI | machine-readable identifier; magnetic resonance imaging; medical records information; Medical Resear... |
| MRN | malignant renal neoplasm |
| system | <biology, ecology> A group of related natural objects or forces within a defined zone, a regularly interacting or interdependent group of items forming a unified whole, a more general and less rigorous term than ecosystem. (09 Oct 1997) |
|---|---|
| system of macrophages | A widely distributed collection of both free and fixed macrophages derived from bone marrow precursor cells by way of monocytes; their substantial phagocytic activity is mediated by immunoglobulin and the serum complement system. In both connective and lymphoid tissue, they may occur as free and fixed macrophages; in the sinusoids of the liver, as Kupffer cells; in the lung, as alveolar macrophages; and in the nervous system, as microglia. Synonym: system of macrophages. (05 Mar 2000) |
| system, parasympathetic nervous | : A part of nervous system that slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles. The parasympathetic nervous system together with the sympathetic nervous system (that accelerates the heart rate, constricts blood vessels, and raises blood pressure) constitute the autonomic nervous system. (12 Dec 1998) |
| system, sympathetic nervous | A part of nervous system that accelerates the heart rate, constricts blood vessels, and raises blood pressure. The sympathetic nervous system together with the parasympathetic nervous system (that slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles) constitute the autonomic nervous system. (12 Dec 1998) |
| diagnostic techniques, digestive system | Methods and procedures for the diagnosis of diseases or dysfunction of the digestive system or its organs or demonstration of their physiological processes. (12 Dec 1998) |
| diagnostic techniques, respiratory system | Methods and procedures for the diagnosis of diseases of the respiratory tract or its organs. It includes respiratory function tests. (12 Dec 1998) |
| digestive system | The organs that are responsible for getting food into and out of the body and for making use of food to keep the body healthy. These include the mouth, oesophagus, stomach, liver, gallbladder, pancreas, small intestine, colon, and rectum. (12 Dec 1998) |
| digestive system abnormalities | Congenital structural abnormalities of the digestive system. (12 Dec 1998) |
| digestive system fistula | An abnormal passage communicating between any parts of the digestive system or between any part of the digestive system and other organs. (12 Dec 1998) |
| digestive system surgical procedures | Surgery performed on the digestive system or its parts. (12 Dec 1998) |
| dopaminergic system | The system of nerve cells that uses dopamine asits neurotransmitter. (22 May 1997) |
| duffy blood-group system | A blood group consisting mainly of the antigens fy(a) and fy(b), determined by allelic genes, the frequency of which varies profoundly in different races; amorphic genes are common. (12 Dec 1998) |
| I blood-group system | A blood group related both to the abo and p systems that includes several different antigens found in most people on erythrocytes, in milk, and in saliva. The antibodies react only at low temperatures. (12 Dec 1998) |
| imhoff treatment system | In waste water treatment, a tank without aeration or oxygenation where solids settle out. The solids are digested in a separate compartment in the bottom. (05 Dec 1998) |
| immune system | <immunology> The body system, made up of many organs and cells, that defends the body against infection, disease and foreign substances. The immune system is often stimulated in specific ways to fight cancer cells. (16 Dec 1997) |