| lemniscus medialis | A band of white fibres originating from the gracile and cuneate nuclei and decussating in the lower medulla; thence it passes upward through the centre of the medulla oblongata, close to the median raphe; on entering the pons it spreads out laterally to form a flat band ascending over the dorsal border of the pontine nuclei; in the mesencephalon it passes over the dorsal border of the substantia nigra and is displaced laterally by the red nucleus; passing medial to the medial geniculate body, the bundle enters and terminates in the ventral posterior nucleus of the thalamus. Throughout their course, the fibres retain a somatotopic order such that those originating from the gracile nucleus and representing the lower extremity lie lateral to those originating in the cuneate nucleus and representing the arm. The medial lemniscus conveys somatic-sensory information involved in tactile discrimination (two-point discrimination), position sense, and vibration sense. Synonym: lemniscus medialis, medial fillet, Reil's band, Reil's ribbon. (05 Mar 2000) |
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| ligamentum medialis | <anatomy> The part of the medial or deltoid ligament that extends from the medial malleolus to the neck of the talus. Synonym: pars tibiotalaris anterior ligamenti medialis, anterior talotibial ligament, anterior tibiotalar part of deltoid ligament, ligamentum medialis, ligamentum talotibiale anterius. (05 Mar 2000) |
| abdominal aortic plexus | <anatomy, neurology> An autonomic plexus surrounding the abdominal aorta, directly continuous with the thoracic aortic plexus above and continued inferior to the bifurcation of the aorta as the superior hypogastric plexus. Synonym: plexus aorticus abdominalis. (05 Mar 2000) |
| acromial plexus | A vascular network between the acromion and the skin of the shoulder, formed by anastomoses of the acromial branch of the suprascapular artery with the acromial branch of the thoracoacromial artery. Synonym: rete acromiale, acromial plexus. (05 Mar 2000) |
| annular plexus | A nerve plexus near the corneoscleral junction from which myelinated and unmyelinated nerves pass to the cornea. Synonym: plexus annularis. (05 Mar 2000) |
| anterior coronary plexus | The part of the cardiac plexus that accompanies the coronary arteries on the anterior aspect of the heart. (05 Mar 2000) |
| aortic lymphatic plexus | A plexus of lymph nodes and connecting vessels lying along the lower portion of the abdominal aorta. Synonym: plexus aorticus. (05 Mar 2000) |
| ascending pharyngeal plexus | An autonomic plexus on the artery of the same name, formed of fibres from the superior cervical ganglion. Synonym: plexus pharyngeus ascendens. (05 Mar 2000) |
| Auerbach's plexus | One of two ganglionated neural networks which together form the enteric nervous system. The myenteric (auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (12 Dec 1998) |
| axillary plexus | A lymphatic plexus formed of the lymph nodes, with their afferent and efferent vessels, in the axilla. Synonym: plexus axillaris. (05 Mar 2000) |
| basilar plexus | A venous plexus on the clivus, connected with the cavernous and petrosal sinuses and the internal vertebral (epidural) venous plexus. Synonym: plexus basilaris, basilar sinus. (05 Mar 2000) |
| Batson's plexus | Any of four interconnected venous networks surrounding the vertebral column; anterior external vertebral venous plexus, the small system around the vertebral bodies; posterior external vertebral venous plexus, the extensive system around the vertebral processes; anterior internal vertebral venous plexus, the system running the length of the vertebral canal anterior to the dura; posterior internal vertebral venous plexus, the system running the length of the vertebral canal posterior to the dura; the latter two constitute the epidural venous plexus. Synonym: plexus venosus vertebralis, Batson's plexus, vertebral venous plexus. (05 Mar 2000) |
| batson venous plexus | <radiology> Paravertebral venous plexus, can carry tumour emboli directly to brain from pelvis or abdomen (12 Dec 1998) |
| brachial plexus | A network of lower cervical and upper dorsal spinal nerves supplying the arm, forearm and hand. (27 Sep 1997) |
| brachial plexus neuropathy | A neurological disorder, of unknown cause, characterised by the sudden onset of severe pain, usually about the shoulder and often beginning at night, soon followed by weakness and wasting of various forequarter muscles, particularly shoulder girdle muscles; both sporadic and familial in occurrence with the former much more common; often preceded by some antecedent event, such as an upper respiratory infection, hospitalization, vaccination, or non-specific trauma; usually attributed to a brachial plexus lesion, because the nerve fibres involed are most often derived from the upper trunk, but actually multiple proximal mononeuropathies. Synonym: acute brachial radiculitis, brachial plexitis, brachial plexus neuropathy, Parsonage-Turner syndrome, shoulder-girdle syndrome. (05 Mar 2000) |