| 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) |
| A layer | <molecular biology> Right handed double helical DNA with approximately 11 residues per turn. Planes of base pairs in the helix are tilted 20 deg away from perpendicular to the axis of the helix. Formed from B DNA by dehydration. (18 Nov 1997) |
| ameloblastic layer | The internal layer of the enamel organ. Synonym: enamel layer. (05 Mar 2000) |
| anterior elastic layer | A transparent homogeneous acellular layer, 6 to 9 um thick, lying between the basal lamina of the outer layer of stratified epithelium and the substantia propria of the cornea; considered to be a basement membrane. Synonym: lamina limitans anterior corneae, anterior elastic layer, Bowman's membrane, lamina elastica anterior, limiting layers of cornea. (05 Mar 2000) |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |