| fixation nystagmus | Nystagmus aggravated or induced by ocular fixation, arising as optokinetic nystagmus, or resulting from midbrain lesions. (05 Mar 2000) |
|---|---|
| fixation, ocular | The direction of the gaze so that the visual image of the object falls on the fovea centralis of the retina, the area of the most acute vision. (12 Dec 1998) |
| fixation reaction | <immunology> Binding of complement as a result of its interaction with immune complexes (the classical pathway) or particular surfaces (alternative pathway). (18 Nov 1997) |
| fracture fixation | The use of metallic devices inserted into or through bone to hold a fracture in a set position and alignment while it heals. (12 Dec 1998) |
| fracture fixation, internal | The use of internal devices (metal plates, nails, rods, etc.) to hold the position of a fracture in proper alignment. (12 Dec 1998) |
| latex fixation test | A passive agglutination test in which antigen is adsorbed onto latex particles which then clump in the presence of antibody specific for the adsorbed antigen. Synonym: latex fixation test. (05 Mar 2000) |
| latex fixation tests | Passive agglutination tests in which antigen is adsorbed onto latex particles which then clump in the presence of antibody specific for the adsorbed antigen. (12 Dec 1998) |
| line of fixation | A line joining the object (or point of fixation) with the fovea. (05 Mar 2000) |
| 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) |