| 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) |
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| 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 ganglion | <anatomy> Enlargement of the dorsal root of the spinal cord containing cell bodies of afferent spinal neurons. Neural outgrowth from dorsal root ganglia has been studied extensively in vitro. (18 Nov 1997) |
| spiral cochlear ganglion | An elongated ganglion of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of the modiolus; each ganglion cell gives rise to a peripheral process that passes between the layers of the bony spiral lamina to the organ of Corti, and a central axon that enters the hindbrain as a component of the inferior (cochlear) root of the eighth nerve. Synonym: ganglion spirale cochleae, auditory ganglion, cochlear ganglion, Corti's ganglion, spiral cochlear ganglion. (05 Mar 2000) |
| spiral ganglion | The sensory ganglion of the cochlear nerve. The cells of the spiral ganglion send fibres peripherally to the cochlear hair cells and centrally to the cochlear nuclei of the brainstem. (12 Dec 1998) |
| spiral ganglion of cochlea | An elongated ganglion of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of the modiolus; each ganglion cell gives rise to a peripheral process that passes between the layers of the bony spiral lamina to the organ of Corti, and a central axon that enters the hindbrain as a component of the inferior (cochlear) root of the eighth nerve. Synonym: ganglion spirale cochleae, auditory ganglion, cochlear ganglion, Corti's ganglion, spiral cochlear ganglion. (05 Mar 2000) |
| splanchnic ganglion | Ha small sympathetic ganglion often present in the course of the greater splanchnic nerve. Synonym: ganglion splanchnicum, Lobstein's ganglion. (05 Mar 2000) |
| nasal 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) |
| stellate ganglion | A paravertebral sympathetic ganglion formed by the fusion of the inferior cervical and first thoracic ganglia. (12 Dec 1998) |
| neural ganglion | 1. A knot or knotlike mass. 2. <anatomy> A general term for a group of nerve cell bodies located outside the central nervous system, occasionally applied to certain nuclear groups within the brain or spinal cord, for example basal ganglia. 3. <oncology, tumour> A benign cystic tumour occurring on a aponeurosis or tendon, as in the wrist or dorsum of the foot, it consists of a thin fibrous capsule enclosing a clear mucinous fluid. (18 Nov 1997) |
| nodose ganglion | The inferior (caudal) ganglion of the vagus (10th cranial) nerve. The unipolar nodose ganglion cells are sensory cells with central projections to the medulla and peripheral processes traveling in various branches of the vagus nerve. (12 Dec 1998) |
| sublingual ganglion | A tiny ganglion occasionally found anterior to the submandibular ganglion, of which it is a displaced portion; innervates the sublingual gland. Synonym: ganglion sublinguale. (05 Mar 2000) |
| submandibular ganglion | A small parasympathetic ganglion suspended from the lingual nerve; its postganglionic branches go to the submandibular and sublingual glands; its preganglionic fibres come from the superior salvatory nucleus by way of the chorda tympani. Synonym: ganglion submandibulare, submaxillary ganglion. (05 Mar 2000) |
| submaxillary ganglion | A small parasympathetic ganglion suspended from the lingual nerve; its postganglionic branches go to the submandibular and sublingual glands; its preganglionic fibres come from the superior salvatory nucleus by way of the chorda tympani. Synonym: ganglion submandibulare, submaxillary ganglion. (05 Mar 2000) |
| superior cervical ganglion | The largest and uppermost of the paravertebral sympathetic ganglia. (12 Dec 1998) |