- anterior f. proprius [TA] SYN: fasciculi proprii.
- f. atrioventricularis [TA] SYN: atrioventricular bundle.
- calcarine f. a group of short association fibers beneath the calcarine fissure of the occipital lobe of the cerebrum.
- f. circumolivaris pyramidis an anomalous bundle of nerve fibers on the anterior surface of the medulla oblongata that emerges from the pyramid and curves forward and dorsally over the lower pole of the olive; it is variously interpreted as an aberrant bundle of pontocerebellar fibers or corticopontine fibers.
- cuneate f. [TA] the larger lateral subdivision of the posterior funiculus. SYN: f. cuneatus [TA], Burdach column, Burdach f., Burdach tract, cuneate funiculus, wedge-shaped f..
- f. cuneatus [TA] SYN: cuneate f..
- dorsal longitudinal f. [TA] a bundle of thin, poorly myelinated nerve fibers reciprocally connecting the periventricular zone of the hypothalamus with ventral parts of the central gray substance of the midbrain. SYN: f. longitudinalis posterior [TA], Schütz bundle, tract of Schütz.
- dorsolateral f. [TA] a longitudinal bundle of thin, unmyelinated, and poorly myelinated fibers capping the apex of the posterior horn of the spinal gray matter, composed of posterior root fibers and short association fibers that interconnect neighboring segments of the posterior horn. SYN: posterolateral tract [TA], tractus dorsolateralis [TA], tractus posterolateralis [TA], dorsolateral tract, f. dorsolateralis, f. marginalis, Lissauer bundle, Lissauer column, Lissauer f., Lissauer marginal zone, Lissauer tract, marginal f., Spitzka marginal tract, Spitzka marginal zone, Waldeyer tract, Waldeyer zonal layer.
- f. dorsolateralis SYN: dorsolateral f..
- Flechsig fasciculi f. proprius anterior [TA] and f. proprius lateralis [TA]. See fasciculi proprii.
- fronto-occipital f. SYN: occipitofrontal f..
- gracile f. [TA] the smaller medial subdivision of the posterior funiculus. SYN: f. gracilis [TA], funiculus gracilis, Goll column, posterior pyramid of the medulla, slender f., tract of Goll.
- f. gracilis [TA] SYN: gracile f..
- hooked f. SYN: unciform f..
- inferior longitudinal f. [TA] a well-marked bundle of long association fibers running the whole length of the occipital and temporal lobes of the cerebrum, in part parallel with the inferior horn of the lateral ventricle. SYN: f. longitudinalis inferior [TA].
- interfascicular f. [TA] SYN: semilunar f..
- f. interfascicularis [TA] SYN: semilunar f..
- intersegmental fasciculi SYN: fasciculi proprii.
- lateral f. proprius [TA] SYN: fasciculi proprii.
- lenticular f. [TA] the pallidal efferent fibers that cross the internal capsule and are insinuated between the subthalamic nucleus and zona incerta; they join in the formation of the thalamic f.. SEE ALSO: lenticular loop. SYN: f. lenticularis [TA].
- f. lenticularis [TA] SYN: lenticular f..
- Lissauer f. SYN: dorsolateral f..
- fasciculi longitudinales ligamenti cruciformis atlantis [TA] SYN: longitudinal bands of cruciform ligament of atlas, under band.
- fasciculi longitudinales pontis SYN: longitudinal pontine fasciculi.
- longitudinal pontine fasciculi the massive bundles of corticofugal fibers passing longitudinally through the ventral part of pons; they are composed of corticoreticular, tectopontine, corticopontine, corticonuclear (corticobulbar), and corticospinal fibers. SYN: fasciculi longitudinales pontis, longitudinal pontine bundles.
- macular f. the collection of fibers in the optic nerve directly connected with the macula lutea. SYN: f. macularis.
- f. macularis SYN: macular f..
- mammillotegmental f. [TA] a small bundle of fibers that passes dorsalward from the mamillary body for a short distance with the mamillothalamic tract, then turns down the brainstem to reach the dorsal and ventral tegmental nuclei of the mesencephalon. SYN: f. mammillotegmentalis [TA].
- f. mammillotegmentalis [TA] SYN: mammillotegmental f..
- mammillothalamic f. [TA] a compact, thick bundle of nerve fibers that passes dorsalward from the mamillary body on either side to terminate in the anterior nucleus of the thalamus. SYN: f. mammillothalamicus, f. thalamomammillaris, mamillothalamic tract, Vicq d'Azyr bundle.
- f. mammillothalamicus SYN: mammillothalamic f..
- marginal f. SYN: dorsolateral f..
- f. marginalis SYN: dorsolateral f..
- medial longitudinal f. [TA] a longitudinal bundle of fibers extending from the upper border of the mesencephalon into the cervical segments of the spinal cord, located close to the midline and ventral to the central gray matter; it is composed largely of fibers from the vestibular nuclei ascending to the motor neurons innervating the external eye muscles (abducens, trochlear, and oculomotor nuclei), and descending to spinal cord segments innervating the musculature of the neck. SYN: f. longitudinalis medialis [TA], Collier tract, medial longitudinal bundle, posterior longitudinal bundle.
- f. of Meynert SYN: retroflex f..
- oblique pontine f. a bundle of fibers in the ventral surface of the pons running from the anterior mesial portion outward and backward. SYN: f. obliquus pontis, oblique bundle of pons.
- occipitofrontal f. association fibers consisting of upper (superior occipitofrontal f. [TA]) and lower (inferior occipitofrontal f. [TA]) bundles that extend from occipital to frontal lobes of the cerebral hemisphere. SYN: fronto-occipital f..
- f. occipitofrontalis See occipitofrontal f..
- f. pedunculomammillaris SYN: peduncle of mammillary body.
- pedunculomammillary f. SYN: peduncle of mammillary body.
- perpendicular f. a bundle of association fibers running vertically and interconnecting regions of the temporal, occipital, and parietal lobes.
- posterior f. proprius [TA] SYN: fasciculi proprii.
- proper fasciculi SYN: fasciculi proprii.
- fasciculi proprii (f. proprius anterior [TA], f. proprius lateralis [TA], f. proprius posterior [TA]); ascending and descending spinospinal association fiber systems of the spinal cord that lie in the anterior, lateral, and posterior funiculi at the gray matter-white matter interface. SYN: anterior f. proprius [TA], lateral f. proprius [TA], posterior f. proprius [TA], ground bundles, intersegmental fasciculi, lateral proprius bundle, proper fasciculi.
- f. proprius anterior [TA] the ground bundle of the anterior column of the spinal cord. See fasciculi proprii. SYN: anterior ground bundle.
- f. proprius lateralis [TA] See fasciculi proprii.
- retroflex f. [TA] a compact bundle of fibers arising in the habenula and passing ventralward to the interpeduncular nucleus at the base of the midbrain; part of its fibers bypass this nucleus and terminate in the raphe nuclei of the caudal mesencephalic tegmentum. SYN: f. retroflexus [TA], habenulointerpeduncular tract, habenulopeduncular tract [TA], tractus habenulointerpeduncularis [TA], f. of Meynert, habenulopeduncular tract, retroflex bundle of Meynert.
- f. retroflexus [TA] SYN: retroflex f..
- f. rotundus SYN: solitary tract.
- round f. SYN: solitary tract.
- rubroreticular fasciculi bundles of fibers that connect the red nucleus to the pontine and midbrain reticular nuclei. SYN: fasciculi rubroreticulares.
- fasciculi rubroreticulares SYN: rubroreticular fasciculi.
- semilunar f. [TA] a compact bundle composed of descending branches of posterior root fibers located near the border between the fasciculi gracilis and cuneatus of the cervical and thoracic spinal cord; it corresponds to the septomarginal f., Hoche 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. SYN: f. interfascicularis [TA], interfascicular f. [TA], f. semilunaris, comma bundle of Schultze, comma tract of Schultze.
- f. septomarginalis [TA] SYN: septomarginal f..
- slender f. SYN: gracile f..
- f. solitarius SYN: solitary tract.
- solitary f. SYN: solitary tract.
- subcallosal f. a bundle of thin nerve fibers 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 fibers projecting from the cerebral cortex to the caudate nucleus. SYN: f. subcallosus for superior occipitofrontal f..
- subthalamic f. [TA] nerve fibers crossing the internal capsule between the subthalamic nucleus and the globus pallidus; this f. contains pallidosubthalamic and subthalamopallidal fibers. SYN: f. subthalamicus [TA].
- f. subthalamicus [TA] SYN: subthalamic f..
- superior longitudinal f. [TA] long association fiber bundle lateral to the centrum ovale of the cerebral hemisphere, connecting the frontal, occipital, and temporal lobes; the fibers pass from the frontal lobe through the operculum to the posterior end of the lateral sulcus where many fibers radiate into the occipital lobe and others turn downward and forward around the putamen and pass to anterior portions of the temporal lobe. SYN: f. longitudinalis superior [TA], arcuate f. (1).
- thalamic f. [TA] nerve fibers forming a composite bundle containing cerebellothalamic (crossed) and pallidothalamic (uncrossed) fibers that is insinuated between the thalamus and zona incerta. SEE ALSO: fields of Forel, under field. SYN: f. thalamicus [TA].
- f. thalamicus [TA] SYN: thalamic f..
- f. thalamomammillaris SYN: mammillothalamic f..
- transverse fasciculi [TA] SYN: fasciculi transversi.
- fasciculi transversi [TA] the transversely directed fibers in the distal portions of the palmar and plantar aponeuroses. SYN: transverse fasciculi [TA].
- unciform f., uncinate f. [TA] a band of long association fibers 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. SYN: f. uncinatus [TA], arcuate f. (2), frontotemporal tract, hooked f., temporofrontal tract.
- uncinate f. of cerebellum [TA] fastigial efferent fibers that cross within the cerebellum and descend over the lateral surface of the superior cerebellar peduncle; these fibers largely terminate in the vestibular nuclei and the reticular formation of the pons and medulla. SYN: f. uncinatus cerebelli [TA], hooked bundle of Russell, uncinate bundle of Russell, uncinate f. of Russell.
- f. uncinatus [TA] SYN: unciform f..
- f. uncinatus cerebelli [TA] SYN: uncinate f. of cerebellum.
- wedge-shaped f. SYN: cuneate f..
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a) a bundle of skeletal muscle cells bound together by fasciae and forming one of the constituent elements of a muscle
b) a bundle of nerve fibers that follow the same course but do not necessarily have like functional connections (as in some subdivisions of the funiculi of the spinal cord) compare TRACT (2)
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n.
a bundle, e.g. of nerve or muscle fibres.
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fas·cic·u·lus (fə-sikґu-ləs) gen. and pl. fasciґculi [L. dim. of fascis bundle] 1. a fascicle; a small bundle or cluster. 2. [TA] a small bundle of nerve, muscle, or tendon fibers. 3. a tract, bundle, or group of nerve fibers that are more or less associated functionally; see also under bundle, lemniscus, tract, and tractus.Descriptions of anatomic structures are given on TA terms, and include anglicized names of specific fasciculi.
Medical dictionary. 2011.