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ganglion[gang´gle-on] (pl. gan´glia, ganglions) (Gr.)
1. a knot or knotlike mass; in anatomic nomenclature, a group of nerve cell bodies located outside the central nervous system. The term is occasionally applied to certain nuclear groups within the brain or spinal cord, such as the basal ganglia.
2. a form of cystic tumor occurring on an aponeurosis or tendon, as in the wrist. adj., adj gan´glial, ganglion´ic.
autonomic ganglia aggregations of cell bodies of neurons of the autonomic nervous system; the parasympathetic and the sympathetic ganglia combined.
basal ganglia basal nuclei.
cardiac ganglia ganglia of the superficial cardiac plexus under the arch of the aorta.
carotid ganglion an occasional small enlargement in the internal carotid plexus.
celiac ganglia two irregularly shaped ganglia, one on each crus of the diaphragm within the celiac plexus.
cerebrospinal ganglia those associated with the cranial and spinal nerves.
1. any of the three ganglia (inferior, middle, and superior) of the sympathetic trunk in the neck region.
2. one near the cervix uteri.
cervicothoracic ganglion a ganglion on the sympathetic trunk anterior to the lowest cervical or first thoracic vertebra. It is formed by a union of the seventh and eighth cervical and first thoracic ganglia. Called also stellate ganglion.
cervicouterine ganglion one near the cervix uteri.
ciliary ganglion a parasympathetic ganglion in the posterior part of the orbit.
cochlear ganglion the sensory ganglion located within the spiral canal of the modiolus. It consists of bipolar cells that send fibers peripherally to the organ of Corti and centrally to the cochlear nuclei of the brainstem. Called also spiral ganglion and Corti's ganglion.
Corti's ganglion cochlear ganglion.
craniospinal ganglia collections of sensory neurons that form nodular enlargements on the dorsal roots of the spinal nerves and on the sensory roots of cranial nerves.
dorsal root ganglion spinal ganglion.
false ganglion an enlargement of a nerve that does not have a true ganglionic structure.
Frankenhäuser's ganglion cervical ganglion (def. 2).
gasserian ganglion trigeminal ganglion.
geniculate ganglion the sensory ganglion of the facial nerve, on the geniculum of the facial nerve.
ganglion im´par a ganglion commonly found on the front of the coccyx, where the sympathetic trunks of the two sides unite.
1. the lower of two ganglia of the glossopharyngeal nerve as it passes through the jugular foramen.
2. the lower of two ganglia of the vagus nerve as it passes through the jugular foramen.
jugular ganglion superior ganglion (defs. 1 and 2).
Ludwig's ganglion a ganglion near the right atrium of the heart, connected with the cardiac plexus.
lumbar ganglia the ganglia on the sympathetic trunk, usually four or five on either side.
lymphatic ganglion lymph node.
otic ganglion a parasympathetic ganglion next to the medial surface of the mandibular division of the trigeminal nerve, just inferior to the foramen ovale. Its postganglionic fibers supply the parotid gland.
parasympathetic ganglia aggregations of cell bodies of cholinergic neurons of the parasympathetic nervous system; these ganglia are located near to or within the wall of the organs being innervated. See also Plates.
petrous ganglion inferior ganglion (def. 1).
pterygopalatine ganglion a parasympathetic ganglion in a fossa in the sphenoid bone, formed by postganglionic cell bodies that synapse with preganglionic fibers from the fascial nerve via the nerve of the pterygopalatine canal. Called also sphenopalatine ganglion.
sacral ganglia those of the sacral part of the sympathetic trunk, usually three or four on either side.
Scarpa's ganglion vestibular ganglion.
sensory ganglion any of the ganglia of the peripheral nervous system that transmit sensory impulses; also, the collective masses of nerve cell bodies in the brain subserving sensory functions.
simple ganglion a cystic tumor in a tendon sheath.
sphenopalatine ganglion pterygopalatine ganglion.
spinal ganglion the cerebrospinal ganglion on the dorsal root of each spinal nerve; called also dorsal root ganglion.
spiral ganglion cochlear ganglion.
stellate ganglion cervicothoracic ganglion.
submandibular ganglion a parasympathetic ganglion located superior to the deep part of the submandibular gland, on the lateral surface of the hyoglossal muscle; its postganglionic fibers supply the sublingual and submandibular glands.
1. the upper of two ganglia on the glossopharyngeal nerve as it passes through the jugular foramen.
2. the upper of two ganglia of the vagus nerve just as it passes through the jugular foramen. Called also jugular ganglion.
sympathetic ganglia aggregations of cell bodies of adrenergic neurons of the sympathetic nervous system; these ganglia are arranged in chainlike fashion on either side of the spinal cord. See also Plates.
thoracic ganglia the ganglia on the thoracic portion of the sympathetic trunk, 11 or 12 on either side.
trigeminal ganglion a ganglion on the sensory root of the fifth cranial nerve, situated in a cleft within the dura mater on the anterior surface of the pars petrosa of the temporal bone, and giving off the ophthalmic and maxillary and part of the mandibular nerve. Called also gasserian or semilunar ganglion.
tympanic ganglion an enlargement on the tympanic branch of the glossopharyngeal nerve.
vestibular ganglion the sensory ganglion of the vestibular part of the eighth cranial nerve, located in the upper part of the lateral end of the internal acoustic meatus. Called also Scarpa's ganglion.
Walther's ganglion glomus coccygeum.
Wrisberg's ganglia cardiac ganglia.
wrist ganglion cystic enlargement of a tendon sheath on the back of the wrist.
originally, all the large masses of gray matter at the base of the cerebral hemisphere; as currently used, the striate body (caudate and lentiform nuclei); cell groups functionally associated with the striate body, such as the subthalamic nucleus and substantia nigra are frequently, but incorrectly, grouped as part of the basal nuclei/ganglia.
See also: basal nuclei.
See also: basal nuclei.
Etymology: Gk, basis + ganglion, knot
the islands of gray matter, largely composed of cell bodies, within each cerebral hemisphere. The most important are the caudate nucleus, the putamen, the substantia nigra, the subthalamic nucleus, and the pallidum. The basal ganglia are surrounded by the rings of the limbic system and lie between the thalamus of the diencephalon and the white matter of the hemisphere.
ba·sal gan·gli·a(bā'săl gang'glē-ă)
Large masses of gray matter at the base of the cerebral hemisphere: the striate body (caudate and lentiform nuclei) and cell groups associated with the striate body, such as the subthalamic nucleus and substantia nigra.
basal gangliaThe discrete, grey nerve cell masses lying deep in the lower part of the brain within the white matter. They consist, on each side, of the caudate nucleus, the putamen and the globus pallidus. They receive numerous connections from the outer layer (cortex) of the CEREBRUM, above, and from the CEREBELLUM, behind. They are concerned with the control of motor function.
A structure at the base of the brain composed of four groups of nerve cells, responsible for body movements and coordination.
basal gangliacentral nervous system ganglia (i.e. caudate nucleus and putamen [i.e. the striatum], lentiform nucleus and substantia nigra) that control and coordinate fine movement; their output inhibits movement (other than postural reflexes) when at rest, and assists movement initiation by inhibiting postural reflexes
pertaining to or situated near a base; in physiology, pertaining to the lowest possible level.
the structure that acts as a template for the characteristic 9 + 2 arrangement of the microtubules of eukaryotic cilia and flagella.
basal cell tumors
neoplasms of the multipotential cells within the stratum germinativum of the skin. They are common in dogs and cats, are locally expansive and do not metastasize.
basal energy requirements (BER)
see energy requirements.
a collection of masses of gray matter at the base of the cerebral hemispheres, subthalamus and midbrain which are responsible for much of the organization of the activity of somatic muscles. The individual nuclei are the caudate nucleus, putamen, globus pallidus, endopeduncular nucleus, subthalamic nucleus and the substantia nigra. Other nuclei which have a similar function but are usually not included in the group are the amygdaloid nuclei and the red nucleus.
see stratum basale.
the deepest layer of the epidermis in the avian skin. Called also dermoepidermal junction.
basal metabolic rate
see metabolic rate.
the minimal energy expended for the maintenance of respiration, circulation, peristalsis, muscle tonus, body temperature, glandular activity and the other vegetative functions of the body. See also metabolic rate.
basal metabolism test
a method of measuring the body's expenditure of energy by recording its rate of oxygen intake and consumption. Once a major test of thyroid gland function, it is being replaced by diagnostic tests requiring less extensive preparation and capable of producing more accurate test results, e.g. the determination of the levels of thyroid hormones in the blood and the radioiodine uptake test.
see basal ganglion.
the ventral plate of the developing neural tube of the embryo; associated with motor output from the CNS.
degree of contractile tension remaining in blood vessels after complete elimination of all external excitatory influences.