| ventral nucleus of trapezoid body | A cell group embedded among the fibres of the trapezoid body, the major decussation of the central auditory pathway, in the lower pons. The nucleus receives fibres from the contralateral cochlear nuclei and contributes fibres to the ascending auditory system or lateral lemniscus. Synonym: nucleus ventralis corporis trapezoidei. (05 Mar 2000) |
|---|---|
| dorsal nucleus of trapezoid body | A circumscript, bipartite cell group located ventrolaterally in the lower pontine tegmentum, immediately dorsal to the trapezoid body; the nucleus receives fibres from both the ipsilateral and contralateral cochlear nuclei, and contributes fibres to the lateral (auditory) lemniscus of both sides. It is believed to be prominently involved in the function of spatial localization of sound. Synonym: nucleus dorsalis corporis trapezoidei, oliva superior, superior olivary nucleus, superior olive. (05 Mar 2000) |
| trapezoid body | A plate of transverse fibres running over the dorsal (deep) border of the pontine nuclei; it is formed by ascending auditory fibres that cross to the opposite side of the brainstem. Synonym: corpus trapezoideum, trapezoid. (05 Mar 2000) |
| nuclei of mamillary body | A single large-celled lateral nucleus and a larger bipartite medial nucleus together comprising the mamillary body; present in the caudal hypothalamus. Synonym: nuclei corporis mamillaris, nucleus of the mamillary body. (05 Mar 2000) |
| trapezoid | 1. <geometry> A plane four-sided figure, having two sides parallel to each other. 2. <anatomy> A bone of the carpus at the base of the second metacarpal, or index finger. Origin: Gr. Trapezoid-shaped; table + shape, likeness: cf. F. Trapezoide. See Trapezium. 1. Having the form of a trapezoid; trapezoidal; as, the trapezoid ligament which connects the coracoid process and the clavicle. 2. <anatomy> Of or pertaining to the trapezoid ligament; as, the trapezoid line. Source: Websters Dictionary (01 Mar 1998) |
| trapezoid bone | A bone in the distal row of the carpus; it articulates with the second metacarpal, trapezium, capitate, and scaphoid. Synonym: os trapezoideum, lesser multangular bone, os multangulum minus, trapezoid. (05 Mar 2000) |
| trapezoid ligament | <anatomy> The lateral part of the coracoclavicular ligament that attaches to the trapezoid line of the clavicle. Synonym: ligamentum trapezoideum. (05 Mar 2000) |
| trapezoid line | The area on the inferior surface of the clavicle near its lateral extremity on which the trapezoid ligament attaches. Synonym: linea trapezoidea, trapezoid ridge. (05 Mar 2000) |
| trapezoid ridge | The area on the inferior surface of the clavicle near its lateral extremity on which the trapezoid ligament attaches. Synonym: linea trapezoidea, trapezoid ridge. (05 Mar 2000) |
| accessory olivary nuclei | See: dorsal accessory olivary nucleus, medial accessory olivary nucleus. (05 Mar 2000) |
| anterior nuclei of thalamus | Collective term for three groups of nerve cells which together form the anterior thalamic tubercle: the anteroventral nuclei, a relatively large nucleus; the anteromedial nuclei; and the anterodorsal nuclei, a small (but large-celled) nucleus. The nuclei receive the mamillothalamic tract from the mamillary body, and additional afferents by way of the fornix; they project collectively to the cortex of the cingulate and parahippocampal gyrus. Synonym: nuclei anteriores thalami. (05 Mar 2000) |
| arcuate nuclei | A variable assembly of small cell groups, probably outlying components of the pontine nuclei, on the ventral and medial aspects of the pyramid in the medulla oblongata. Synonym: nuclei arcuati. (05 Mar 2000) |
| autonomic nuclei | Nuclei located in the spinal cord (T1-L2, S2-S4) and in the brainstem (Edinger-Westphal nucleus, superior and inferior salivatory nuclei, dorsal vagal nucleus and parts of the ambiguus nucleus) from which general visceral efferent preganglionic fibres arise; may be sympathetic (T1-L2) or parasympathetic (craniosacral); hypothalamic nuclei/areas function in concert with autonomic nuclei. (05 Mar 2000) |
| basal nuclei | Nucleus of the cerebral hemisphere that originally included the caudate and lenticular nuclei, the claustrum and the amygdaloid body (complex); functionally the term basal nuclei now specifies the caudate and lenticular nuclei and adjacent cell groups having important connections therewith (subthalamic nucleus; substantia nigra, partes compacta and reticulata); amygdaloid complex now known to be part of the limbic system. Synonym: nuclei basales. (05 Mar 2000) |
| branchiomotor nuclei | Collective term for those motoneuronal nuclei of the brainstem (n. Ambiguus, facial motor nucleus, motor nucleus of the trigeminus) that develop from the branchiomotor column of the embryo and innervate striated muscle fibres (muscles of mastication, facial musculature, pharynx and vocal cord muscles) developed from the mesenchyme of the branchial arches. Synonym: special visceral efferent nuclei, special visceral motor nuclei. (05 Mar 2000) |