Medical Dictionary Definitions A-Z List
Medical Dictionary Definitions A - Z - «D»:
Deer mouse: A deceptively cute rodent capable of carrying the types of hantavirus that cause HPS (hantavirus pulmonary syndrome) in the US. The deer mouse has big eyes and big ears. Its head and body are normally about 2 to 3 inches long, and the tail adds another 2 to 3 inches in length. It occurs ...
Deerfly fever: An infection in rabbits and other wild rodents caused by the bacterium Francisella tularensis that can be transmitted to humans by contact with infected animal tissues or ticks. Also called tularemia.
The main mode of transmission to humans is tick bites in the summer and exposure t...
Defecation syncope: The temporary loss of consciousness (syncope) upon defecating (having a bowel movement). Syncope is the temporary loss of consciousness or, in plain English, fainting. The situations that trigger this reaction are diverse and include having blood drawn, straining while urinating...
Defect, atrial septal (ASD)
Defect, atrial septal (ASD): A hole in the septum, the
wall, between the atria, the upper chambers of the heart. Commonly called an ASD. ASDs are
a major class of congenital cardiac malformation....
Defect, enzyme: An abnormality in the protein (enzyme)
important in catalyzing a normal biochemical reaction in the body. Disorders result from a
deficiency (or functional abnormality) of an enzyme. Archibald Garrod in 1902 was the
first to attribute a disease to an enzyme defect: an inborn error of...
Defect, neural tube
Defect, neural tube: A major birth defect caused by abnormal development of the neural tube, the structure present during embryonic life which gives rise to the central nervous system -- the brain and spinal cord. Neural tube defects (NTDs) are among the most common birth defects that cause infant m...
Defect, ventricular septal (VSD)
Defect, ventricular septal (VSD): A hole in the septum (the wall) between the lower chambers of the heart (the ventricles).
Ventricular Septal Defect is the most common type of heart malformation (congenital heart disease). At least 1 baby in every 500 is born with a VSD.
A VSD lets blood from t...
Defensin: A family of potent antibiotics made within the body by neutrophils (a type of white blood cell) and macrophages (cells that can engulf foreign particles). The defensins play important roles against invading microbes. They act against bacteria, fungi and viruses by binding to their membrane...
Defensive medicine: Medical
practices designed to avert the future possibility of malpractice suits. In
defensive medicine, responses are undertaken primarily to avoid liability rather
than to benefit the patient. Doctors may order tests, procedures, or visits, or
avoid high-risk patients or pro...
Defibrillation: The use of a carefully controlled
electric shock, administered either through a device on the
exterior of the chest wall or directly to the exposed heart
muscle, to restart or normalize heart rhythms....
Defibrillator: A device used to correct a dangerously abnormal heart rhythm, usually ventricular fibrillation, or to restart the heart by depolarizing its electrical conduction system and delivering brief measured electrical shocks to the chest wall or the heart muscle itself....
Defibrillator storm: A condition that arises when a defibrillator implanted in the chest to right an arrhythmia (an abnormal heart rhythm) fires off frequently --sometimes several times a day or even more often -- each time with a jolt like a boxer's punch to the chest, because of far advanced heart...
Defibrillator, automated external
Defibrillator, automated external: See: Automated external defibrillator....
Defibrillator, implantable cardiac
Defibrillator, implantable cardiac: A device put within the body that is designed to recognize certain types of abnormal heart rhythms (arrhythmias) and correct them.
Defibrillators continuously monitor the heart rhythm in order to detect rapid arrhythmias such as
Ventricular tachycardia (rapid re...
Deficiency, adenosine deaminase (ADA)
Deficiency, adenosine deaminase (ADA): A genetic (inherited) condition that results in a immune deficiency disorder called severe combined immunodeficiency disease. Adenosine deaminase is an enzyme that plays a key role in salvaging purine molecules.
ADA deficiency is of special interest in the hi...