| crossed extension reflex | Extension of the contralateral hind limb when the paw of an animal is painfully stimulated or the central cut end of an afferent nerve, e.g., the peroneal, is stimulated; sometimes occurs in humans upon tapping the skin. (05 Mar 2000) |
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| Buck's extension | Apparatus for applying longitudinal skin traction on the leg through contact between the skin and adhesive tape; friction between the tape and skin permits application of force, which is applied through a cord over a pulley, suspending a weight; elevation of the foot of the bed allows the body to act as a counterweight. Synonym: Buck's traction. (05 Mar 2000) |
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| paraplegia in extension | Paralysis of the legs, maintained in an extended position by hypertonic extensor muscles. (05 Mar 2000) |
| ridge extension | An intraoral surgical operation for deepening the labial, buccal, and/or lingual sulci; it is performed to increase the intraoral height of the alveolar ridge in order to assist denture retention. (05 Mar 2000) |
| primer extension | A technique for determining the 5'-untranslated region of a specific mRNA molecule. Uses an oligonucleotide complementary to the known RNA sequence as a primer for cDNA synthesis via reverse transcriptase. (05 Mar 2000) |
| skeletal extension | Traction pull on a bone structure mediated through pin or wire inserted into the bone to reduce a fracture of long bones. Synonym: skeletal extension. (05 Mar 2000) |
| nail extension | An obsolete method of extension, by a weight on a nail or pin in the distal fragment of a fracture. (05 Mar 2000) |
| extension | 1. <orthopaedics> The movement by which the two elements of any jointed part are drawn away from each other. 2. <anatomy> A movement which brings the members of a limb into or toward a straight relation. Origin: L. Extensio (18 Nov 1997) |
| extension bridge | A fixed partial bridge denture in which the pontic is retained only on one side by an abutment tooth. Synonym: extension bridge. (05 Mar 2000) |
| extension form | The extension of the cavity preparation outline form to include areas of incipient carious lesions; this extension provides a dental restoration with margins that are self-cleansing or easily cleaned. (05 Mar 2000) |
| crossed adductor jerk | Contraction of the adductors of the thigh and inward rotation of the limb elicited by tapping the sole. Synonym: crossed adductor jerk. (05 Mar 2000) |
| crossed adductor reflex | Contraction of the adductors of the thigh and inward rotation of the limb elicited by tapping the sole. Synonym: crossed adductor jerk. (05 Mar 2000) |
| crossed anaesthesia | Anaesthesia of one side of the head and the other side of the body due to a brainstem lesion. (05 Mar 2000) |
| crossed aphasia | Aphasia in a right-handed person due to a solely right cerebral lesion. (05 Mar 2000) |
| crossed cylinders | A lens used in refraction to determine the strength and axis of a cylindrical lens to correct astigmatism; a combination of concave and convex cylinders of like power whose axes are at right angles to each other. (05 Mar 2000) |
| crossed embolism | Passage of a clot (thrombus) from a vein to an artery. When clots in veins break off (embolise) , they travel first to the right side of the heart and, normally, then to the lungs where they lodge. The lungs act as a filter to prevent the clots from entering the arterial circulation. However, when there is a hole in the wall between the two upper chambers of the heart (an atrial septal defect), a clot can crossparadoxically from the right to the left side of the heart, then pass into the arteries. Once in the arterial circulation, a clot can travel to the brain, block a vessel there, and cause a stroke (cerebrovascular accident). Because of the risk of stroke from crossed embolism, it is usually recommended that even small atrial septal defects be closed (repaired). Also called: paradoxical embolism. (12 Dec 1998) |