| long-term potentiation | <physiology> Increase in the strength of transmission at a synapse with repetitive use that lasts for more than a few minutes. As a form of long term synaptic plasticity it is important as a possible cellular mechanism for the basis of learning and memory storage. It has been studied most extensively at excitatory synapses onto principal neurons of the hippocampus where it was first demonstrated. Selective inhibition of NMDA receptor channels has been shown to block long-term potentiation and to block spatial learning. (12 Dec 1998) |
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| long-term productivity | The capacity of a site to support forest ecosystems over generations of humans and trees as measured against some defined reference. (05 Dec 1998) |
| long-term survival | <oncology> Term used to describe the survival of leukaemia patients who have been disease free for prolonged periods of time, usually at least five years. The chance of disease returning (relapse) decreases with time. (13 Nov 1997) |
| long thoracic artery | <anatomy, artery> Origin, axillary; distribution, muscles of chest and mammary gland. Synonym: arteria thoracica lateralis, external mammary artery, long thoracic artery. (05 Mar 2000) |
| long thoracic nerve | <anatomy, nerve> Arises from the fifth, sixth, and seventh cervical nerves (roots of brachial plexus), descends the neck behind the brachial plexus, and is distributed to the serratus anterior muscle; it is somewhat unusual in that it courses on the superficial aspect of the muscle is supplies; its paralysis results in "winged scapula". Synonym: nervus thoracicus longus, Bell's respiratory nerve, external respiratory nerve of Bell, posterior thoracic nerve. (05 Mar 2000) |
| long thoracic vein | <anatomy, vein> Incorrect term for lateral thoracic vein. (05 Mar 2000) |
| long ton | (shipping ton) 2,240 pounds. Commonly used in Great Britain. (05 Dec 1998) |
| long-tongue | torticollis Previous: writing, writing hand, wrongful life, wrought wire, wrybill, wrymouthNext: wry neck, wuchereria, wuchereria bancrofti, Wuchereria malayilong-tongue -->wry neck 1. A twisted or distorted neck; a deformity in which the neck is drawn to one side by a rigid contraction of one of the muscles of the neck; torticollis. Medically called spasmodic torticollis, or torticollis. The most common of the focal dystonias. In torticollis, the muscles in the neck that control the position of the head are affected, causing the head to twist and turn to one side. In addition, the head may be pulled forward or backward. 2. <ornithology> Any one of several species of Old World birds of the genus Jynx, allied to the woodpeckers; especially, the common European species (J. Torguilla); so called from its habit of turning the neck around in different directions. Synonym: cuckoo's mate, snakebird, summer bird, tonguebird, and writheneck. Source: Websters Dictionary (01 Mar 1998) |
| long vinculum | A long, threadlike band that extends from the dorsal surface of each of the flexor tendons of a digit to the proximal phalanx. Synonym: vinculum longum. (05 Mar 2000) |
| long-winded | Long-breathed; hence, tediously long in speaking; consuming much time; as, a long-winded talker. Long-windedness, "A tedious, long-winded harangue." (South) Source: Websters Dictionary (01 Mar 1998) |
| abdominal external oblique muscle | <anatomy, muscle> Origin, fifth to twelfth ribs; insertion, anterior half of lateral lip of iliac crest, inguinal ligament, and anterior layer of the rectus sheath; action, diminishes capacity of abdomen, draws thorax downward; nerve supply, thoracoabdominal nerves. Synonym: musculus obliquus externus abdominis, abdominal external oblique muscle. (05 Mar 2000) |
| abdominal internal oblique muscle | <anatomy, muscle> Origin, iliac fascia deep to lateral part of inguinal ligament, anterior half of crest of ilium, and lumbar fascia; insertion, tenth to twelfth ribs and sheath of rectus; some of the fibres from inguinal ligament terminate in the conjoint tendon; action, diminishes capacity of abdomen, flexes lumbar vertebral column (bends thorax forward); nerve supply, lower thoracic. Synonym: musculus obliquus internus abdominis, abdominal internal oblique muscle. (05 Mar 2000) |
| abdominal muscle deficiency syndrome | <syndrome> Congenital absence (partial or complete) of abdominal muscles, in which the outline of the intestines is visible through the protruding abdominal wall; in males, genitourinary anomalies (urinary tract dilation and cryptorchidism) are also found; genetics unclear. (05 Mar 2000) |
| abductor digiti minimi muscle of foot | Origin, lateral and medial processes of calcanean tuberosity; insertion, lateral side of proximal phalanx of fifth toe; action, abducts and flexes little toe; nerve supply, lateral plantar nerve. Synonym: musculus abductor digiti minimi pedis, abductor muscle of little toe, musculus abductor digiti quinti. (05 Mar 2000) |
| abductor digiti minimi muscle of hand | Origin, pisiform bone and pisohamate ligament; insertion, medial side of base of proximal phalanx of the little finger; action, abducts and flexes little finger; nerve supply, ulnar. Synonym: musculus abductor digiti minimi manus, abductor muscle of little finger, musculus abductor digiti quinti. (05 Mar 2000) |