| Ur | urea; urine, urinary |
|---|---|
| US | screen unsharpness ultrasonic, ultrasound; ultrasonography; unconditioned stimulus; unique sequence;... |
| USI | universal serial interface; urinary stress incontinence |
| UT | total unsharpness; Ullrich-Turner [syndrome]; Unna-Thost [syndrome]; untested; untreated; urinary tr... |
| UTO | upper tibial osteotomy; urinary tract obstruction |
| hypophysial portal system | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
|---|---|
| hypophysioportal system | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
| hypothalamo-hypophyseal system | A neuroendocrine system of neurons, fibre tracts, endocrine tissue, and blood vessels which produces and releases pituitary hormones into the systemic circulation. (12 Dec 1998) |
| hypothalamohypophysial portal system | A capillary network that carries hypophyseotropic hormones from the hypothalamus, where they are secreted into blood, to their sites of action in the anterior hypophysis. See: portal circulation, hypophysis, hypothalamus. Synonym: hypophyseoportal system, hypophysial portal circulation, hypophysial portal system, hypophysioportal system, hypothalamohypophysial portal circulation, hypothalamohypophysial portal system. (05 Mar 2000) |
| hypoxia warning system | A device designed to produce an audio or visual signal at a predetermined level of oxygen partial pressure; ideally, the system would warn of impending hypoxia in time for corrective action to be taken. (05 Mar 2000) |
| solar system | The group of celestial bodies, including the earth, orbiting around and gravitationally bound by the sun. It includes nine planets, 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as minor planets (asteroids) and meteoroids. (12 Dec 1998) |
| somesthetic system | Sensory data derived from skin, muscles, and body organs in contrast to that derived from the five special senses. (05 Mar 2000) |
| SOS system | The DNA repair system also called error prone repair in which apurinic DNA molecules are repaired by incorporation of a base that may be the wrong base but that permits replication. RecA protein is required for this type of repair. SOS genes function in control of the cell cycle in pro and eu karyotes. (18 Nov 1997) |
| static system | That part of the neuromuscular system whereby the animal organism is maintained in posture and equilibrium, and counteracts the forces of gravity and atmospheric pressure; distinguished from the kinetic system. (05 Mar 2000) |
| nervous system | The entire integrated system of nerve tissue in the body: the brain, brainstem, spinal cord, nerves and ganglia. (16 Dec 1997) |
| nervous system abnormalities | Congenital structural abnormalities of the nervous system. (12 Dec 1998) |
| nervous system, autonomic | Part of the nervous system once thought functionally independent of the brain. The autonomic nervous system regulates key functions including the activity of the cardiac (heart) muscle, smooth muscles (e.g., of the gut), and glands. The autonomic nervous system has two divisions: (1) the sympathetic nervous system, which accelerates the heart rate, constricts blood vessels, and raises blood pressure; and (2) the parasympathetic nervous system, which slows the heart rate, increases intestinal and gland activity, and relaxes sphincter muscles. (12 Dec 1998) |
| nervous system, parasympathetic | A part of the 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) |
| nervous system physiology | Functions and activities of the nervous system as a whole or with reference to the peripheral or the central nervous system. (12 Dec 1998) |
| nervous system, sympathetic | A part of the 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) |