| hysterical spinal neuralgia | Simulating Pott's disease, following a trauma. (05 Mar 2000) |
|---|---|
| Soemmerring's ganglion | A large cell mass, crescentic on transverse section, extending forward over the dorsal surface of the crus cerebri from the rostral border of the pons into the subthalamic region; it is composed of a dorsal stratum of closely spaced pigmented (i.e., melanin-containing) cells, the pars compacta, and a larger ventral region of widely scattered cells, the pars reticulata; the pars compacta in particular includes numerous cells that project forward to the striatum (caudate nucleus and putamen) and contain dopamine, which acts as the transmitter substance at their synaptic endings; other, apparently non-dopaminergic cells of the substantia nigra project to a rostral part of the ventral nucleus of thalmus, the middle layers of the superior colliculus and to restricted parts of the reticular formation of the midbrain; the nigrostriatal projection is reciprocated by a massive striatonigral fibre system with multiple neurotransmitters, chief among which is gamma-aminobutyric acid (GABA); substantia n. Receives smaller afferent projections from the subthalamic nucleus, the lateral segment of the globus pallidus, the dorsal nucleus of the raphe and the pedunculopontine nucleus of the midbrain. The pars reticulata forms part of the output system for the striate body. The substantia n. Is involved in the metabolic disturbances associated with Parkinson's disease and Huntington's disease. Synonym: locus niger, nucleus niger, Soemmerring's ganglion. (05 Mar 2000) |
| spastic spinal paralysis | A type of cerebral palsy in which there is bilateral spasticity, with the lower extremities more severely affected. Compare: flaccid paralysis. Synonym: Erb-Charcot disease, infantile diplegia, Little's disease, spastic spinal paralysis, tabes spasmodica. (05 Mar 2000) |
| sphenopalatine ganglion | A small parasympathetic ganglion in the upper part of the pterygopalatine fossa whose postsynaptic fibres supply the lacrimal, nasal, palatine and pharyngeal glands. Synonym: ganglion pterygopalatinum, Meckel's ganglion, nasal ganglion, sphenopalatine ganglion. (05 Mar 2000) |
| spinal | <anatomy> Pertaining to a spine or to the vertebral column. Origin: L. Spinalis (18 Nov 1997) |
| spinal accessory nerve | <anatomy, nerve> The eleventh cranial nerve enervates the sternocleidomastoid muscles and the trapezius muscles. Lesions of the eleventh result in drooping of the shoulder and inability to rotate the head away from the affected side. (27 Sep 1997) |
| spinal anaesthesia | A form of regional anaesthesia that involves the injection of an anaesthetic into the epidural space (in the spinal canal), at predetermined location along the spine, to produce anaesthesia in all body regions that are supplied by nerves that arise below the anatomic region of the block. Often used for obstetrical procedures. Origin: Gr. Aisthesis = sensation (27 Sep 1997) |
| spinal anaesthetic | A local anaesthetic agent producing loss of sensation when injected into the subarachnoid space. (05 Mar 2000) |
| spinal analgesia | Euphemism for spinal anaesthesia. (05 Mar 2000) |
| spinal apoplexy | Stroke involving the spinal cord. (05 Mar 2000) |
| spinal arteries | Branches of the following arteries which supply the meninges, the roots of the spinal nerves, and in some cases, the spinal cord: 1) vertebral, 2) ascending cervical, 3) dorsal branch of posterior intercostal I to XI, 4) dorsal branch of subcostal, 5) dorsal branch of lumbar arteries, 6) lumbar branch of iliolumbar, 7) lateral sacral; all spinal arteries give rise to radicular arteries supplying dorsal and ventral roots of spinal nerves, but some (4-9), are large enough to reach and anastomose with the anterior and posterior spinal arteries. Synonym: rami radiculares. See: medullary spinal arteries, arteria radicularis magna. Synonym: rami spinales. (05 Mar 2000) |
| spinal ataxia | Ataxia due to spinal cord disease, as in tabes dorsalis. (05 Mar 2000) |
| spinal bifida | A congenital defect in which the neural arches fail to close, so exposing the contents of the spinal canal posteriorly. Usually occurring in the lumbosacral region (lower back) of the spine. (27 Sep 1997) |
| spinal block | An obstruction to the flow of cerebrospinal fluid in the spinal subarachnoid space; used inaccurately to refer to spinal anaesthesia. (05 Mar 2000) |
| spinal canal | The canal that contains the spinal cord, spinal meninges, and related structures. It is formed by the vertebral foramina of successive vertebrae of the articulated vertebral column. Synonym: canalis vertebralis, spinal canal, tubus vertebralis. (05 Mar 2000) |