| marginal part of orbicularis oris muscle | <anatomy> The part of the orbicularis oris muscle located in the margin of the lips, i.e., the red area. Synonym: pars marginalis musculi orbicularis oris. (05 Mar 2000) |
|---|---|
| marginal rays | In geometric optics, those ray's originating from the periphery. (05 Mar 2000) |
| marginal ridge | The rounded borders which form the mesial and distal margins of the occlusal surface of a tooth. Synonym: crista marginalis, marginal ridge. (05 Mar 2000) |
| marginal ring ulcer of cornea | A slowly advancing intermittent ulcer involving the circumference of the corneal margin. (05 Mar 2000) |
| marginal sphincter | A thickening of circular musculature at the free margin of the ileal papilla. Synonym: ileocaecocolic sphincter, marginal sphincter, operculum ilei, Varolius' sphincter. (05 Mar 2000) |
| marginal tentorial branch of internal carotid artery | <anatomy, artery> A small branch from the cavernous part of the internal carotid artery to the free margin of the tentorium. Synonym: ramus marginalis tentorii arteriae carotidis internae. (05 Mar 2000) |
| marginal zone | The outer, nonnuclear layer of the embryonic neural tube; into its fibrous network grow the longitudinal nerve fibres which eventually become the white matter of the cord and brain stem. Synonym: marginal zone. (05 Mar 2000) |
| posterior marginal vein | It originates on the superior surface of the corpus callosum and runs posteriorly to terminate in the great cerebral vein. Synonym: dorsal callosal vein, dorsal vein of corpus callosum, posterior marginal vein, posterior pericallosal vein. (05 Mar 2000) |
| Spitzka's marginal tract | 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) |
| Spitzka's marginal zone | 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) |
| Terrien's marginal degeneration | A form of marginal corneal degeneration. (05 Mar 2000) |
| ectatic marginal degeneration of cornea | Bilateral opacification and vascularization of the periphery of the cornea, progressing to formation of a gutter and ectasia. Synonym: ectatic marginal degeneration of cornea. (05 Mar 2000) |
| Lissauer's marginal zone | 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) |
| accessory tubercle | A small apophysis at the posterior part of the base of the transverse process of each of the lumbar vertebrae. Synonym: processus accessorius, accessory tubercle. (05 Mar 2000) |
| acoustic tubercle | The slight prominence of the floor of the lateral recess of the fourth ventricle, corresponding to the underlying cochlear and vestibular nuclei. Synonym: acoustic tubercle, trigonum acustici. (05 Mar 2000) |