| masseter reflex | A spasmodic contraction of the temporal muscles following a downward tap on the loosely hanging mandible. Synonym: chin jerk, chin reflex, jaw jerk, mandibular reflex, masseter reflex. (05 Mar 2000) |
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| masseter | <anatomy, muscle> Origin, superficial part: inferior border of the anterior two-thirds of the zygomatic arch; deep part: inferior border and medial surface of the zygomatic arch; insertion, lateral surface of ramus and coronoid process of the mandible; action, elevates mandible (closes jaw); nerve supply, masseteric branch of mandibular division of trigeminal. Synonym: musculus masseter. (06 Mar 2000) |
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| masseter muscle | <anatomy> A masticatory muscle whose action is closing the jaws. (12 Dec 1998) |
| musculus masseter | <anatomy> A masticatory muscle whose action is closing the jaws. (12 Dec 1998) |
| superficial part of masseter muscle | superficial part of masseter muscle |
| deep part of masseter muscle | deep part of masseter muscle |
| abdominocardiac reflex | Mechanical stimulation (usually distention) of abdominal viscera causing changes (usually a slowing) in the heart rate or the occurrence of extrasystoles. (05 Mar 2000) |
| Abrams' heart reflex | A contraction of the myocardium when the skin of the precordial region is irritated. (05 Mar 2000) |
| accommodation reflex | Increased convexity of the lens, due to contraction of the ciliary muscle and relaxation of the suspensory ligament, to maintain a distinct retinal image. (05 Mar 2000) |
| Achilles reflex | A contraction of the calf muscles when the tendo calcaneus is sharply struck. Synonym: ankle jerk, ankle reflex, tendo Achillis reflex, triceps surae reflex. (05 Mar 2000) |
| acousticopalpebral reflex | A form of the wink reflex in which there is a contraction, sometimes very slight, of the orbicularis palpebrarum muscle when a sudden noise is made close to the ear; it is absent in labyrinthine disease with total deafness. Synonym: acousticopalpebral reflex, auropalpebral reflex, cochleo-orbicular reflex, startle reflex. (05 Mar 2000) |
| acquired reflex | A reflex that is gradually developed by training and association through the frequent repetition of a definite stimulus. See: conditioning. Synonym: acquired reflex, behaviour reflex, trained reflex. (05 Mar 2000) |
| acromial reflex | Contraction of the biceps muscle caused by a tap on the acromion or the coracoid process. (05 Mar 2000) |
| acute reflex bone atrophy | Atrophy of bones, commonly of the carpal or tarsal bones, following a slight injury such as a sprain. See: causalgia, reflex sympathetic dystrophy. Synonym: acute reflex bone atrophy, posttraumatic osteoporosis, Sudeck's syndrome. Origin: L. English sweat (05 Mar 2000) |
| adductor reflex | Contraction of the adductors of the thigh caused by tapping the tendon of the adductor magnus muscle while the thigh is abducted. (05 Mar 2000) |
| anal reflex | Contraction of the internal sphincter gripping the finger passed into the rectum. (05 Mar 2000) |