| lateral cerebral fissure | The deepest and most prominent of the cortical fissures, extending from the anterior perforated substance first laterally at the deep incisure between the frontal and temporal lobes, then back and slightly upward over the lateral aspect of the cerebral hemisphere, with the superior temporal gyrus as its lower bank, the insula forming its greatly expanded floor. Two short side branches, the ramus anterior and ramus ascendens, divide the inferior frontal gyrus into an orbital part, triangular part, and opercular part. Synonym: sulcus lateralis cerebri, fissura cerebri lateralis, lateral cerebral fissure, sylvian fissure, fissure of Sylvius. (05 Mar 2000) |
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| left sagittal fissure | A sagittal groove on the undersurface of the liver formed by the fissura ligamenti teretis anteriorly and the fissura ligamenti venosi posteriorly. (05 Mar 2000) |
| linguogingival fissure | A fissure sometimes occurring on the lingual surface of one of the upper incisors and extending into the cementum. (05 Mar 2000) |
| longitudinal fissure of cerebrum | The deep cleft separating the two hemispheres of the cerebrum. Synonym: fissura longitudinalis cerebri, great longitudinal fissure. (05 Mar 2000) |
| lunate fissure | A small, inconstant semilunar groove on the cortical convexity near the occipital pole, marking the anterior border of the striate cortex (area 17) and considered homologous with the major sulcus of the same name that is a more constant feature of the cerebral cortex in monkeys and apes. Synonym: sulcus lunatus cerebri, ape fissure, lunate fissure, lunate sulcus, simian fissure. (05 Mar 2000) |
| Aaron's sign | <clinical sign> In acute appendicitis, a referred pain or feeling of distress in the epigastrium or precordial region on continuous firm pressure over McBurney's point. (05 Mar 2000) |
| Abadie's sign of tabes dorsalis | Insensibility to pressure over the tendo achillis. (05 Mar 2000) |
| Abrahams' sign | <clinical sign> An obsolete sign: Rales and other adventitious sounds, changes in the respiratory murmurs, and increase in the whispered sound can be heard on auscultation over the acromial end of the clavicle some time before they become audible at the apex; heard primarily in pulmonary tuberculosis affecting the apical portion of the lung, a dull-flat note, i.e., one between the normal dullness at the right apex and absolute flatness, heard on percussion in that region, indicating progress from incipient to advanced tuberculosis. (05 Mar 2000) |
| accessory sign | <clinical sign> A finding frequently but not consistently present in a disease. Synonym: assident sign. (05 Mar 2000) |
| Allis' sign | <clinical sign> In fracture of the neck of the femur, the trochanter rides up, relaxing the fascia lata, so that the finger can be sunk deeply between the great trochanter and the iliac crest. (05 Mar 2000) |
| Amoss' sign | <clinical sign> In painful flexion of the spine, it is necessary to support a sitting position by extending the arms behind the torso with the weight placed on the hands. (05 Mar 2000) |
| Anghelescu's sign | <clinical sign> In vertebral tuberculosis, painful or impossible flexion of the spine when the patient attempts to rest weight on the heels and occiput. (05 Mar 2000) |
| antecedent sign | <clinical sign> A sign that appears during the prodrome of a disease. Synonym: antecedent sign. (05 Mar 2000) |
| assident sign | <clinical sign> A finding frequently but not consistently present in a disease. Synonym: assident sign. (05 Mar 2000) |
| Auenbrugger's sign | <clinical sign> An epigastric prominence seen in cases of marked pericardial effusion. (05 Mar 2000) |