| communicating branches of spinal nerves | Short nerves arising from the initial portion of the ventral primary rami of the thoracic and upper lumbar spinal nerves through which all presynaptic sympathetic nerve fibres must pass to reach the sympathetic trunks; also conveyed by the white rami communicans are visceral afferent (sensory) fibres which were conveyed to the sympathetic trunks in splanchnic nerves. Most fibres conveyed by the white rami communicantes are myelinated. Synonym: rami communicantes nervorum spinalium, communicating branches of spinal nerves. (05 Mar 2000) |
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| communicating rami of spinal nerves | The communicating branches of spinal nerves, small bundles of nerve fibres connecting spinal nerves with sympathetic ganglia; the fibres passing from the ganglion to the spinal nerve are nonmyelinated and are called gray rami communicantes, those passing in the reverse direction are myelinated and are called white rami communicantes. (05 Mar 2000) |
| plexus of spinal nerves | An intermingling of fibre fascicles from adjacent spinal nerves to form a network; the major plexus's are the cervical, brachial, and lumbosacral. Synonym: plexus nervorum spinalium. (05 Mar 2000) |
| muscular atrophy, spinal | Progressive degenerative disorder of motor neurons in the spinal cord, brainstem, and motor cortex, manifested clinically by muscular weakness, atrophy, and corticospinal tract signs in varying combinations. (12 Dec 1998) |
| continuous spinal anaesthesia | Insertion of a catheter into the spinal subarachnoid space and leaving it in situ to permit serial intermittent injection of local anaesthetic solution for prolonged spinal anaesthesia. Synonym: fractional spinal anaesthesia. (05 Mar 2000) |
| cornua of spinal cord | The posterior or occipital division of the lateral ventricle of the brain, extending backward into the occipital lobe; the posterior gray column of the spinal cord as appearing in cross section. Synonym: cornu posterius ventriculi lateralis, cornu posterius, cornua of spinal cord, occipital horn. (05 Mar 2000) |
| posterior branch of spinal nerves | See: dorsal primary ramus of spinal nerve. (05 Mar 2000) |
| posterior column of spinal cord | The pronounced, dorsolaterally oriented ridge of gray matter in each lateral half of the spinal cord, corresponding to the posterior or dorsal horn appearing in transverse sections of the cord. Synonym: columna posterior, dorsal column of spinal cord, posterior column of spinal cord. (05 Mar 2000) |
| posterior median fissure of spinal cord | A shallow furrow in the median line of the posterior surface of the spinal cord. Synonym: sulcus medianus posterior medullae spinalis, posterior median fissure of spinal cord. (05 Mar 2000) |
| posterior median sulcus of spinal cord | A shallow furrow in the median line of the posterior surface of the spinal cord. Synonym: sulcus medianus posterior medullae spinalis, posterior median fissure of spinal cord. (05 Mar 2000) |
| posterior spinal artery | <anatomy, artery> Origin, vertebral; distribution, medulla, spinal cord, and pia mater; anastomoses, spinal branches of intercostal arteries. Synonym: arteria spinalis posterior. (05 Mar 2000) |
| posterior spinal sclerosis | See Tabes dorsalis. (12 Dec 1998) |
| posterior white column of the spinal cord | The large wedge-shaped fibre bundle lying between the posterior gray column and the posterior median septum, and composed largely of dorsal root fibres. Synonym: funiculus posterior, dorsal funiculus, funiculus dorsalis. (05 Mar 2000) |
| sacral part of spinal cord | The part of the cord from which consists of the five sacral segments of the spinal cord (S1-S5) and from which five pairs of sacral nerves originate. Synonym: pars sacralis medullae spinalis, segmenta medullae spinalis sacralia. (05 Mar 2000) |
| progressive infantile spinal muscular atrophy | Transmitted as autosomal recessive on chromosome 5q. Progressive dysfunction of the anterior horn cells in the spinal cord and brainstem cranial nerves with profound weakness and bulbar dysfunction occurring in the first two years of life. Three groups, based on age of clinical onset, are recognised. Synonym: familial spinal muscular atrophy, Hoffmann's muscular atrophy, infantile muscular atrophy, infantile progressive spinal muscular atrophy, progressive infantile spinal muscular atrophy, Werdnig-Hoffmann disease, Werdnig-Hoffmann muscular atrophy. (05 Mar 2000) |