Dictionary

syncope, defecation The temporary loss of consciousness upon defecating (having a bowel movement). See also syncope; syncope, situational; vasovagal reaction.

syncope, coughing The temporary loss of consciousness upon coughing. See also syncope; syncope, situational; vasovagal reaction.

syncope Partial or complete loss of consciousness, with interruption of awareness of self and surroundings and spontaneous recovery that is due to a temporary reduction in blood flow and therefore a shortage of oxygen to the brain. This leads to lightheadedness or a “blackout” episode (loss of consciousness). Heart conditions that can cause syncope include…

synchronic study A study that is done at a single point in time rather than over the course of a period of time (longitudinally).

synapse A specialized junction at which a neural cell (neuron) communicates with a target cell. At a synapse, a neuron releases a chemical transmitter that diffuses across a small gap and activates special sites called receptors on the target cell. The target cell may be another neuron or a specialized region of a muscle or…

symptom Any subjective evidence of disease. In contrast, a sign is objective. Blood coming out a nostril is a sign; it is apparent to the patient, physician, and others. Anxiety, low back pain, and fatigue are all symptoms; only the patient can perceive them.

symphysis pubis The area in the front of the pelvis where the pubic bones meet.

symphysiotomy A surgical procedure that has been used to effect an immediate dramatic increase in the size of the pelvic outlet to permit delivery of a baby. The cartilage of the area where the pubic bones come together (symphysis pubis) is surgically divided.

sympathetic ophthalmia Inflammation of the uveal tract of the uninjured eye (sympathizing eye) some weeks after a wound involving the uveal tract of the other eye (exciting eye). Also known as transferred ophthalmia.

sympathetic nervous system A part of the nervous system that serves to accelerate the heart rate, constrict blood vessels, and raise blood pressure. The sympathetic nervous system and the parasympathetic nervous system constitute the autonomic nervous system.

symmetric lipomatosis, multiple See cephalothoracic lipodystrophy.

Sydenham’s chorea A disorder that emerges after a bout of rheumatic fever and is most frequently seen in children. The choreaform movements associated with the disease are twisting. Sydenham’s chorea can be treated with medication. See also PANDAS; rheumatic fever.