| slender fasciculus | gracile fasciculus |
|---|---|
| solitary fasciculus | A slender, compact fibre bundle extending longitudinally through the dorsolateral region of the medullary tegmentum, surrounded by the nucleus of the solitary tract, below the obex decussating over the central canal, and descending over some distance into the upper cervical segments of the spinal cord. It is composed of primary sensory fibres that enter with the vagus, glossopharyngeal, and facial nerves, and in part convey information from stretch receptors and chemoreceptors in the walls of the cardiovascular, respiratory, and intestinal tracts; in rostral parts of the tract impulses are generated by the receptor cells of the taste buds in the mucosa of the tongue. Its fibres are distributed to the nucleus of the solitary tract. Synonym: tractus solitarius, fasciculus rotundus, fasciculus solitarius, funiculus solitarius, Gierke's respiratory bundle, Krause's respiratory bundle, round fasciculus, solitary bundle, solitary fasciculus. (05 Mar 2000) |
| subcallosal fasciculus | A bundle of thin nerve fibres running longitudinally beneath the corpus callosum in the angle between the latter and the caudate nucleus; it forms an anterior continuation of the tapetum of the temporal lobe and appears to consist largely of fibres projecting from the cerebral cortex to the caudate nucleus. Synonym: fasciculus subcallosus. (05 Mar 2000) |
| subthalamic fasciculus | Nerve fibres crossing the internal capsule between the subthalamic nucleus and the globus pallidus; this fasciculus contains pallidosubthalamic and subthalamopallidal fibres. (05 Mar 2000) |
| nucleus of cuneate fasciculus | The larger Burdach's nucleus; one of the three nuclei of the posterior column of the spinal cord; located near the dorsal surface of the medulla oblongata at and below the level of the obex, the nucleus receives posterior root fibres corresponding to the sensory innervation of the arm and hand of the same side; together with its medial companion, the gracile nucleus, it is the major source of origin of the medial lemniscus. Synonym: nucleus cuneatus, Burdach's nucleus, nucleus funiculi cuneati, nucleus of cuneate fasciculus. (05 Mar 2000) |
| dorsolateral fasciculus | A longitudinal bundle of thin, unmyelinated and poorly myelinated fibres capping the apex of the posterior horn of the spinal gray matter, composed of posterior root fibres and short association fibres that interconnect neighboring segments of the posterior horn. Synonym: fasciculus dorsolateralis, tractus dorsolateralis, dorsolateral tract, fasciculus marginalis, Lissauer's bundle, Lissauer's column, Lissauer's fasciculus, Lissauer's marginal zone, Lissauer's tract, marginal fasciculus, Spitzka's marginal tract, Spitzka's marginal zone, Waldeyer's tract, Waldeyer's zonal layer. (05 Mar 2000) |
| interfascicular fasciculus | A compact bundle composed of descending branches of posterior root fibres located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal fasciculus, Hoche's tract, or oval area of Flechsig in the lumbar, and to the triangle of Philippe-Gombault in the sacral spinal segments; like these, it can be demonstrated only in cases of demyelination resulting from dorsal root lesions. Synonym: fasciculus semilunaris, fasciculus interfascicularis, comma bundle of Schultze, comma tract of Schultze, interfascicular fasciculus. (05 Mar 2000) |
| oblique pontine fasciculus | A bundle of fibres in the ventral surface of the pons running from the anterior mesial portion outward and backward. Synonym: fasciculus obliquus pontis, oblique bundle of pons. (05 Mar 2000) |
| occipitofrontal fasciculus | A bundle of association fibres extending from the frontal to the occipital lobes of the cerebrum. Synonym: fasciculus occipitofrontalis, fronto-occipital fasciculus. (05 Mar 2000) |
| oval fasciculus | A compact bundle composed of descending branches of posterior root fibres located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal fasciculus, Hoche's tract, or oval area of Flechsig in the lumbar, and to the triangle of Philippe-Gombault in the sacral spinal segments; like these, it can be demonstrated only in cases of demyelination resulting from dorsal root lesions. Synonym: fasciculus semilunaris, fasciculus interfascicularis, comma bundle of Schultze, comma tract of Schultze, interfascicular fasciculus. (05 Mar 2000) |
| thalamic fasciculus | Nerve fibres forming a composite bundle containing cerebellothalamic (crossed) and pallidothalamic (uncrossed) fibres that is insinuated between the thalamus and zona incerta. See: fields of Forel. Synonym: fasciculus thalamicus. (05 Mar 2000) |
| unciform fasciculus | A band of long association fibres reciprocally connecting the frontal and temporal lobes of the cerebrum, running caudally through the white matter of the frontal lobe, sharply curving ventrally under the stem of the sylvian fissure, and then fanning out to the cortex of the anterior half of the superior and middle temporal gyri. Synonym: fasciculus uncinatus, arcuate fasciculus, frontotemporal tract, hooked fasciculus, temporofrontal tract. (05 Mar 2000) |
| uncinate fasciculus of Russell | Fastigial efferent fibres that cross with the cerebellum and descend over the lateral surface of the superior cerebellar peduncle; these fibres largely terminate in the vestibular nuclei and the reticular formation of the pons and medulla. Synonym: hooked bundle of Russell, uncinate fasciculus of Russell. (05 Mar 2000) |
| fasciculus | Origin: L. See Fascicle. 1. A little bundle; a fascicle. 2. A division of a book. Source: Websters Dictionary (01 Mar 1998) |
| fasciculus anterior proprius | The ground bundle of the anterior column of the spinal cord. See: fasciculi proprii. Synonym: anterior ground bundle. Origin: L. Dim. Of fascis, bundle (05 Mar 2000) |