| Flynn phenomenon | A pupillary response to light, the reverse of that expected; e.g., contraction of the pupil in response to turning the lights off. Synonym: Flynn phenomenon, paradoxical pupillary phenomenon. (05 Mar 2000) |
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| Friedreich's phenomenon | The tympanitic percussion sound over a pulmonary cavity is slightly raised in pitch on deep inspiration. (05 Mar 2000) |
| Leclef phenomenon | Enhanced phagocytosis by leukocytes of microorganisms in the presence of immune serum. (05 Mar 2000) |
| Leede-Rumpel phenomenon | Appearance of petechiae in an area following application of vascular constriction, such as by a tourniquet, usually after 10 minutes but can appear after shorter period, such as following application of tourniquet to draw blood specimen or use of blood pressure cuff. Due to capillary fragility or abnormal platelet numbers (e.g. Thrombocytopenia) or function. (05 Mar 2000) |
| leg phenomenon | In tetany, spasm both of the extensor muscles of the knee and of the calf muscles when the extended leg is flexed at the hip. Synonym: leg phenomenon, Pool-Schlesinger sign, Schlesinger's sign. In tetany, contraction of the arm muscles following the stretching of the brachial plexus by elevation of the arm above the head with the forearm extended, resembles the contraction resulting from stimulation of the ulnar nerve. Synonym: arm phenomenon. (05 Mar 2000) |
| Leichtenstern's phenomenon | <clinical sign> Tapping gently one of the bones of the extremities causes the patient to draw back violently, sometimes with a loud cry; noted in cases of cerebrospinal meningitis. Synonym: Leichtenstern's phenomenon. (05 Mar 2000) |
| LE phenomenon | The formation of LE cells in bone marrow or blood on adding serum from patients with disseminated lupus erythematosus. (05 Mar 2000) |
| Lucio's leprosy phenomenon | An acute form occurring in pure diffuse lepromatous leprosy presenting irregularly shaped, intensely erythematous, tender plaques, especially of the legs, with tendency to ulceration and scarring. Synonym: lazarine leprosy, Lucio's leprosy phenomenon. (05 Mar 2000) |
| abducens nerve | <anatomy, nerve> The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibres to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control. (12 Dec 1998) |
| abducent nerve | <anatomy> The abducent nerve enervates a muscle which moves the eyeball. Lesions of the sixth cranial nerve result in deviation of the eyeball outward and double vision. Synonym: cranial nerve VI. (27 Sep 1997) |
| accessory nerve | <anatomy, nerve> The accessory nerve enervates the sternocleidomastoid muscles and the trapezius muscles. Lesions of the eleventh result in drooping of the shoulder and inability to rotate the head away from the affected side. Synonym: cranial nerve XI. (27 Sep 1997) |
| accessory nerve lymph nodes | The nodes of the lateral deep cervical group that are located along the accessory nerve; their efferent vessels pass to the supraclavicular lymph nodes. Synonym: companion lymph nodes of accessory nerve, nodi lymphatici comitantes nervi accessorii. (05 Mar 2000) |
| accessory nerve trunk | Part of the accessory nerve formed within the cranial cavity by the union of the cranial and spinal roots, which then divides within the jugular foramen into internal and external branches, the former uniting with the vagus, the latter exiting the foramen as in independent branch which is commonly considered to be the accessory nerve. (05 Mar 2000) |
| accessory portion of spinal accessory nerve | <anatomy, nerve> The roots of the accessory nerve which arise from the medulla; the nerve fibres of the cranial root join the intracranial portion of the vagus nerve and are distributed to the pharyngeal plexus, providing the motor innervation of the soft palate (except the tensor veli palati) and the pharynx. Synonym: pars vagalis nervi accessorii, radices craniales, accessory portion of spinal accessory nerve, cranial roots, vagal part of accessory nerve, vagal part. (05 Mar 2000) |
| accommodation of nerve | <anatomy, nerve> The property of a nerve by which it adjusts to a slowly increasing strength of stimulus, so that its threshold of excitation is greater than it would be were the stimulus strength to have risen more rapidly. (05 Mar 2000) |