| medullary spinal arteries | A large caliber spinal or radicular artery which courses centrally along a dorsal or ventral root, perhaps supplying it and the surrounding meninges in the fashion of any spinal/radicular artery, but which continues on to reach and anastomose with the anterior or posterior (longitudinal) spinal artery. Only 4-9 of the spinal arteries are medullary spinal arteries, found mainly in the lower cervical, lower thoracic and upper lumbar levels, the largest of which is the great radicular artery. (05 Mar 2000) |
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| meningeal branch of spinal nerves | A branch from the initial (mixed) part of each spinal nerve passing in a recurrent fashion back through the intervertebral foramen to supply spinal meninges, the posterior longitudinal ligament, posterolateral periphery of the intervertebral disc, and periosteum of the vertebrae. Synonym: ramus meningeus nervorum spinalium, recurrent meningeal branch of spinal nerves, sinuvertebral nerves. (05 Mar 2000) |
| groove for spinal nerve | <anatomy, nerve> The laterally directed groove on the superior surface of the transverse processes of typical cervical vertebrae between the anterior and posterior tubercles along which the emerging spinal nerve passes. Synonym: sulcus nervi spinalis. (05 Mar 2000) |
| 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) |
| 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) |
| posterior branch of spinal nerves | See: dorsal primary ramus of spinal nerve. (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) |
| 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) |
| progressive spinal amyotrophy | A serious neurologic disease that results from the progressive degeneration of the motor neurons. (27 Sep 1997) |
| progressive spinal muscular atrophy | One of the subgroups of motor neuron disease; a progressive degenerative disorder of the motor neurons of the spinal cord, manifested as progressive, often symmetrical, weakness and wasting, typically beginning in the distal portions of the limbs, particularly in the upper extremities, and spreading proximally; fasciculation potentials are often present, but evidence of corticospinal tract disease (e.g., increased deep tendon reflexes, Babinski sign) is not. (05 Mar 2000) |
| hereditary spinal ataxia | Sclerosis of the posterior and lateral columns of the spinal cord, occurring in children and marked by ataxia in the lower extremities, extending to the upper, followed by paralysis and contractures; autosomal recessive inheritance. See: spinocerebellar ataxia. Synonym: Friedreich's ataxia, heredotaxia. (05 Mar 2000) |