| LASH | left anterior superior hemiblock |
|---|---|
| LSR | lanthanide shift reagent; lecithin/ sphingomyelin ratio; left superior rectus [muscle]; liver/spleen... |
| LSVC | left superior vena cava |
| MSO | management service organization; medial superior olive; medical staff organization |
| OAISO | overaction of the ipsilateral superior oblique |
| fasciculus lateralis proprius | Flechsig's fasciculi or ground bundles (f. Anterior proprius and fasciculus lateralis proprius or lateral ground bundle); intersegmental fasciculi; ascending and descending association fibre systems of the spinal cord which lie deep in the anterior, lateral, and posterior funiculi adjacent to the gray matter. Synonym: ground bundles, intersegmental fasciculi, proper fasciculi. (05 Mar 2000) |
|---|---|
| fasciculus lenticularis | The pallidal efferent fibres that cross the internal capsule and are insinuated between the subthalamic nucleus and zona incerta; they join in the formation of the thalamic fasciculus. See: lenticular loop. Synonym: fasciculus lenticularis. (05 Mar 2000) |
| fasciculus longitudinalis dorsalis | A bundle of thin, poorly myelinated nerve fibres reciprocally connecting the periventricular zone of the hypothalamus with ventral parts of the central gray substance of the midbrain. Synonym: fasciculus longitudinalis dorsalis, Schutz' bundle, tract of Schutz. (05 Mar 2000) |
| fasciculus longitudinalis inferior | A well marked bundle of long association fibres running the whole length of the occipital and temporal lobes of the cerebrum, in part parallel with the inferior horn of the lateral ventricle. Synonym: fasciculus longitudinalis inferior. (05 Mar 2000) |
| fasciculus longitudinalis medialis | A longitudinal bundle of fibres 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 fibres 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. Synonym: fasciculus longitudinalis medialis, Collier's tract, medial longitudinal bundle, posterior longitudinal bundle. (05 Mar 2000) |
| fasciculus macularis | The collection of fibres in the optic nerve directly connected with the macula lutea. Synonym: fasciculus macularis. (05 Mar 2000) |
| fasciculus mamillotegmentalis | A small bundle of fibres 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. Synonym: fasciculus mamillotegmentalis. (05 Mar 2000) |
| fasciculus mamillothalamicus | A compact, thick bundle of nerve fibres that passes dorsalward from the mamillary body on either side to terminate in the anterior nucleus of the thalamus. Synonym: fasciculus mamillothalamicus, fasciculus thalamomamillaris, mamillothalamic tract, Vicq d'Azyr's bundle. (05 Mar 2000) |
| fasciculus marginalis | 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) |
| fasciculus medialis plexus brachialis | In the brachial plexus, the bundle of nerve fibres formed by the anterior division of the inferior trunk which lies medial to the axillary artery; it gives off the medial pectoral nerve, the medial brachial cutaneous, and medial antebrachial cutaneous, nerves and end by dividing into the medial root of the median nerves and the ulnar nerve. Synonym: fasciculus medialis plexus brachialis. (05 Mar 2000) |
| fasciculus obliquus pontis | 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) |
| fasciculus pedunculomamillaris | A fascicle of nerve fibres passing to the mamillary body along the ventral surface of the midbrain; it consists of fibres that originate from the dorsal and ventral tegmental nuclei. Synonym: pedunculus corporis mamillaris, fasciculus pedunculomamillaris, pedunculomamillary fasciculus. (05 Mar 2000) |
| fasciculus posterior plexus brachialis | In the brachial plexus, the bundle of nerve fibres formed by the posterior divisions of the upper, middle and lower trunks which lies posterior to the axillary artery; it gives rise to the upper and lower subscapular and thoracodorsal nerves, terminates by dividing into the axillary, and radial nerves. Synonym: fasciculus posterior plexus brachialis. (05 Mar 2000) |
| fasciculus pyramidalis anterior | Uncrossed fibres forming a small bundle in the pyramidal tract. See: pyramidal tract. Synonym: tractus corticospinalis anterior, tractus pyramidalis anterior, anterior corticospinal tract, anterior pyramidal fasciculus, direct pyramidal tract, fasciculus corticospinalis anterior, fasciculus pyramidalis anterior, Turck's bundle, Turck's column, Turck's tract. (05 Mar 2000) |
| fasciculus pyramidalis lateralis | Those fibres of the pyramidal tract that cross to the opposite side in the pyramidal decussation and descend in the dorsal half of the lateral funiculus of the spinal cord; they are distributed throughout the length of the spinal cord to interneurons of the zona intermedia of the spinal gray matter. See: pyramidal tract. Synonym: tractus corticospinalis lateralis, tractus pyramidalis lateralis, crossed pyramidal tract, fasciculus corticospinalis lateralis, fasciculus pyramidalis lateralis, lateral corticospinal tract, lateral pyramidal fasciculus. (05 Mar 2000) |