| Reil's triangle | A triangular area on the lateral surface of the caudal half of the mesencephalon, bordered caudally by the slight prominence of the lateral lemniscus, dorsally by the base of the inferior colliculus and the brachium of the superior colliculus, and ventrally by the crus cerebri. Synonym: Reil's triangle, triangle of fillet, trigone of fillet, trigonum lemnisci. (05 Mar 2000) |
|---|---|
| cephalic triangle | A triangle on the cranium formed by lines connecting the metopion, the pogonion, and the occipital point. (05 Mar 2000) |
| Gombault's triangle | A compact bundle composed of descending branches of posterior root fibres located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal fasciculus, Hoche's tract, or oval area of Flechsig in the lumbar, and to the triangle of Philippe-Gombault in the sacral spinal segments; like these, it can be demonstrated only in cases of demyelination resulting from dorsal root lesions. Synonym: fasciculus semilunaris, fasciculus interfascicularis, comma bundle of Schultze, comma tract of Schultze, interfascicular fasciculus. (05 Mar 2000) |
| cervical triangle | Any of the triangles of the neck. (05 Mar 2000) |
| Grocco's triangle | A triangular patch of dullness at the base of the chest alongside the spinal column, on the side opposite a pleural effusion. Synonym: paravertebral triangle. (05 Mar 2000) |
| Grynfeltt's triangle | A triangular space bounded above by the end of the last rib and the serratus posterior inferior muscle, anteriorly by the internal oblique, and posteriorly by the quadratus lumborum; lumbar hernia occurs in this space. Synonym: Lesshaft's triangle. (05 Mar 2000) |
| Philippe's triangle | See: semilunar fasciculus. (05 Mar 2000) |
| Ward's triangle | An area of diminished density in the trabecular pattern of the neck of the femur evident by X-ray as well as by direct inspection. (05 Mar 2000) |
| Codman's triangle | In radiology, the interface between growing bone tumour and normal bone, presenting as an incomplete triangle formed by periosteum. (05 Mar 2000) |
| Weber's triangle | On the sole of the foot, an area indicated by the heads of the first and fifth metatarsal bone and the centre of the plantar surface of the heel. (05 Mar 2000) |
| Pirogoff's triangle | A triangle formed by the intermediate tendon of the digastric muscle, the posterior border of the mylohyoid muscle, and the hypoglossal nerve. (05 Mar 2000) |
| colour triangle | A graph on which chromaticity coordinates are plotted. (05 Mar 2000) |
| Wilde's triangle | A triangular area at the anterior inferior part of the tympanic membrane, running from the umbo to the periphery, where there is seen a bright reflection of light. Synonym: cone of light, light reflex, Politzer's luminous cone, red reflex, Wilde's triangle. Malacarne's pyramid, a lobule on the undersurface of the cerebellum, the posterior portion of the vermis. (05 Mar 2000) |
| muscular triangle | The triangle bounded by the sternocleidomastoid muscle, the superior belly of the omohyoid muscle, and the anterior midline of the neck; the infrahyoid muscles occupy most of it. Synonym: trigonum musculare, trigonum omotracheale, inferior carotid triangle, omotracheal triangle, tracheal triangle. (05 Mar 2000) |
| crural triangle | An area of predilection for the petechial initial rash of smallpox; it occupies the lower abdominal, inguinal, and genital regions and the inner aspects of the thighs, the base of the triangle traversing the umbilicus. (05 Mar 2000) |