| HOT | health-oriented telecommunication; human old tuberculin; hyperbaric oxygen therapy; Hypertension Opt... |
|---|---|
| OA | obstructive apnea; occipital artery; occipito-anterior; occiput anterior; octanoic acid; ocular albi... |
| OAA | Old Age Assistance; Older Americans Act; Opticians Association of America; oxaloacetic acid |
| OAB | ABO blood group; old age benefits |
| OAS | old age security; oral allergy syndrome; osmotically active substance |
| ventral nucleus of thalamus | A large, complex cell mass the external border of which forms the ventral and much of the lateral boundary, as well as the rostral border, of the thalamus; it can be subdivided into an anterior, intermediate, and posterior part. Synonym: nucleus ventralis thalami. (05 Mar 2000) |
|---|---|
| ventral posterior intermediate nucleus of thalamus | Intermediate part of the ventrobasal nuclear complex. See: ventral posterior nucleus of thalamus. Synonym: ventral posterior intermediate nucleus of thalamus. (05 Mar 2000) |
| ventral posterior nucleus of thalamus | The large posterior part of the ventral nucleus of the thalamus receiving the somatic sensory lemnisci (medial lemniscus, spinothalamic tract, trigeminal lemniscus) and the ascending gustatory (taste) lemniscus, and projecting in turn by way of the internal capsule to the cortex of the postcentral gyrus. The nucleus is somatotopically organised and subdivided into a ventral posterolateral nucleus of thalamus representing the leg, a ventral posterior intermediate nucleus of thalamus representing the arm, a ventral posteromedial nucleus of thalamus representing the face, and an arcuate nucleus of thalamus receiving the gustatory lemniscus. Synonym: nucleus ventralis posterior thalami, ventrobasal nucleus. (05 Mar 2000) |
| ventral posterolateral nucleus of thalamus | Lateral part of the ventrobasal nuclear complex. See: ventral posterior nucleus of thalamus. Synonym: nucleus ventralis posterolateralis thalami. (05 Mar 2000) |
| medial central nucleus of thalamus | A small cell group in the interthalamic adhesion of the thalamus, occupying the midline region of the internal medullary lamina, between the left and the right paracentral nucleus. Synonym: nucleus medialis centralis thalami. (05 Mar 2000) |
| medial nucleus of thalamus | A large, composite cell group in the dorsomedial region of the thalamus having reciprocal connections with the entire extent of the frontal cortex anterior to the motor cortex (area 4) and premotor cortex (area 6). The afferent connections of the medial nucleus also include projections from the olfactory cortex and amygdala. Synonym: nucleus medialis thalami, dorsomedial nucleus, mediodorsal nucleus. (05 Mar 2000) |
| central lateral nucleus of thalamus | The most lateral of the intralaminar nuclei of the thalamus. Synonym: nucleus centralis lateralis thalami. (05 Mar 2000) |
| medullary laminae of thalamus | Layers of myelinated fibres that appear on transverse sections of the thalamus; the lamina medullaris externa marks the ventral and lateral borders of the thalamus and delimits it from the subthalamus and reticular nucleus of thalamus; the lamina medullaris interna is interposed between the mediodorsal and ventral nuclei of the thalamus and encloses the intralaminar nuclei (centromedian, paracentral, and central lateral nuclei). Synonym: laminae medullares thalami, medullary layers of thalamus. (05 Mar 2000) |
| medullary layers of thalamus | Layers of myelinated fibres that appear on transverse sections of the thalamus; the lamina medullaris externa marks the ventral and lateral borders of the thalamus and delimits it from the subthalamus and reticular nucleus of thalamus; the lamina medullaris interna is interposed between the mediodorsal and ventral nuclei of the thalamus and encloses the intralaminar nuclei (centromedian, paracentral, and central lateral nuclei). Synonym: laminae medullares thalami, medullary layers of thalamus. (05 Mar 2000) |
| medullary stria of thalamus | A narrow, compact fibre bundle that extends along the line of attachment of the roof of the third ventricle to the thalamus on each side and terminates posteriorly in the habenular nucleus. It is composed of fibres originating in the septal area, the anterior perforated substance, the lateral preoptic nucleus, and the medial segment of the globus pallidus. Synonym: stria medullaris thalami, stria fornicis, stria ventriculi tertii. (05 Mar 2000) |
| reticular nucleus of thalamus | A sheet of fairly large neurons covering the lateral, ventral, and rostral surfaces of the thalamus; its reticular appearance is caused by the numerous fascicles of the thalamic peduncles which traverse the nucleus The nucleus receives numerous fibres from the cerebral cortex but it has no cortical projection. Synonym: nucleus reticularis thalami. (05 Mar 2000) |
| posterior medial nucleus of thalamus | Medial part of the ventrobasal nuclear complex. See: ventral posterior nucleus of thalamus. Synonym: nucleus ventralis posteromedialis thalami. (05 Mar 2000) |
| intralaminar nuclei of thalamus | Collective term denoting several cell groups embedded in the internal medullary lamina of the thalamus: central lateral nucleus, paracentral nucleus, and farthest caudally, the large centromedian nucleus. The first two of these receive afferents from the cerebral cortex, brainstem, reticular formation, cerebellum, and spinal cord, and project more or less diffusely to large regions of the frontal and parietal cortex. See: centromedian nucleus. Synonym: nuclei intralaminares thalami. (05 Mar 2000) |
| thalamus | <anatomy> Either of two large, ovoid masses, consisting chiefly of grey substance, situated one on each side of and forming part of the lateral wall of the third ventricle. It is divided into two major parts: dorsal and ventral, each of which contains many nuclei. Origin: L., Gr. Thalamos = inner chamber (18 Nov 1997) |
| lateral nucleus of thalamus | The largest of the major subdivisions of the thalamus; the composite lateral nucleus includes, from before backward, the nucleus lateralis anterior or dorsalis, nucleus lateralis intermedius, nucleus lateralis posterior, and pulvinar; together, these cell groups form most of the free dorsal surface of the posterior half of the thalamus and project to a very large region of parietal, occipitoparietal, and temporal cortex; its afferent connections are largely obscure, but the nucleus lateralis posterior and the pulvinar receive a projection from the superior colliculus. Synonym: nucleus lateralis thalami. (05 Mar 2000) |