| external | <anatomy> Situated or occurring on the outside, many anatomical structures formerly called external are now more correctly termed lateral. Origin: L. Externus = outside (18 Nov 1997) |
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| external absorption | The absorption of substances through skin, mucocutaneous surfaces, or mucous membranes. (05 Mar 2000) |
| external acoustic foramen | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| external acoustic meatus | The passage leading inward through the tympanic portion of the temporal bone, from the auricle to the tympanic membrane; it consists of a bony (inner) portion and a fibrocartilaginous (outer) portion, the cartilaginous external acoustic meatus. Synonym: meatus acusticus externus, acoustic meatus, antrum auris, auditory canal, external auditory meatus. (05 Mar 2000) |
| external acoustic pore | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| external anal sphincter | A fusiform ring of striated muscular fibres surrounding the anus, attached posteriorly to the coccyx and anteriorly to the central tendon of the perineum; it is subdivided, often indistinctly, into a subcutaneous part, a superficial part and a deep part for descriptive purposes. Synonym: musculus sphincter ani externus, external sphincter muscle of anus. (05 Mar 2000) |
| external aperture of cochlear canaliculus | The external opening of the cochlear aqueduct on the temporal bone medial to the jugular fossa. Synonym: apertura externa canaliculi cochleae. (05 Mar 2000) |
| external aperture of vestibular aqueduct | The external opening of the vestibular aqueduct on the posterior surface of the petrous part of the temporal bone near the groove for the sigmoid sinus. Synonym: apertura externa aqueductus vestibuli. (05 Mar 2000) |
| external arcuate fibres | They include: 1) dorsal external arcuate fibres that arise from cells in the accessory or lateral cuneate nucleus and pass to the cerebellum; 2) ventral external arcuate fibres that arise from the arcuate nuclei at the base of the medulla oblongata and pass around the lateral surface of the medulla; both enter the cerebellum as components of the restiform portion of the inferior cerebellar peduncle. Synonym: fibrae arcuatae externae. (05 Mar 2000) |
| external artery of nose | Origin, ophthalmic; external artery of the nose; distribution, skin of side of root of nose; anastomoses, angular artery. Synonym: arteria dorsalis nasi, arteria nasi externa, dorsal artery of nose, external artery of nose. (05 Mar 2000) |
| external auditory foramen | The orifice of the external acoustic meatus in the tympanic portion of the temporal bone. Synonym: porus acusticus externus, external acoustic foramen, external acoustic pore, external auditory pore, external auditory foramen, orifice of external acoustic meatus. (05 Mar 2000) |
| external auditory meatus | The passage leading inward through the tympanic portion of the temporal bone, from the auricle to the tympanic membrane; it consists of a bony (inner) portion and a fibrocartilaginous (outer) portion, the cartilaginous external acoustic meatus. Synonym: meatus acusticus externus, acoustic meatus, antrum auris, auditory canal, external auditory meatus. (05 Mar 2000) |
| external axis of eye | That part of the optic axis from the midpoint of anterior surface of the cornea to the posterior surface of the posterior pole of the external surface of the sclera. Synonym: axis bulbi externus. (05 Mar 2000) |
| external base of skull | External aspect of the base of skull Synonym: norma basilaris, basis cranii externa, norma inferior, norma ventralis. (05 Mar 2000) |
| external branch of accessory nerve | <anatomy, nerve> Portion of the accessory nerve trunk which exits independently from the jugular foramen, carrying fibres from the spinal root of the accessory nerve to the sternocleidomastoid and trapezius muscle. (05 Mar 2000) |
| apertura externa aqueductus vestibuli | The external opening of the vestibular aqueduct on the posterior surface of the petrous part of the temporal bone near the groove for the sigmoid sinus. Synonym: apertura externa aqueductus vestibuli. (05 Mar 2000) |
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| apertura externa canaliculi cochleae | The external opening of the cochlear aqueduct on the temporal bone medial to the jugular fossa. Synonym: apertura externa canaliculi cochleae. (05 Mar 2000) |
| arteria carotis externa | <anatomy, artery> Origin, common carotid at C-4 vertebral level; branches, superior thyroid, lingual, facial, occipital, posterior auricular, ascending pharyngeal, and terminal branches, maxillary and superficial temporal at level of neck of mandible. Synonym: arteria carotis externa. (05 Mar 2000) |
| arteria iliaca externa | <anatomy, artery> Origin, common iliac; branches, inferior epigastric, deep circumflex iliac; becomes the femoral at the inguinal ligament. Synonym: arteria iliaca externa. (05 Mar 2000) |
| arteria maxillaris externa | <anatomy, artery> Origin, external carotid; branches, ascending palatine, tonsillar and glandular branches, submental, inferior labial, superior labial, masseteric, buccal, lateral nasal branches, and angular. Synonym: arteria facialis, arteria maxillaris externa, external maxillary artery. (05 Mar 2000) |
| arteria nasi externa | An alternate term for dorsal nasal artery. Arteria nervorum, arteries to nerves. (05 Mar 2000) |
| auris externa | Which includes the auricle and the external acoustic, or auditory, meatus; the middle ear or the tympanic cavity with its ossicles; and the internal ear or inner ear, or labyrinth, which includes the saemicircular canals, vestibule, and cochlea. See: auricle. Synonym: auris. Origin: A.S. Eare (05 Mar 2000) |
| barotitis externa | This refers to the effect of pressure on the external ear canal. (27 Sep 1997) |
| basis cranii externa | An alternate term for external base of skull. (05 Mar 2000) |
| capsula externa | A thin lamina of white substance separating the claustrum from the putamen. It joins the internal capsule at either extremity of the putamen, forming a capsule of white matter external to the lenticular nucleus. Synonym: capsula externa, periclaustral lamina. (05 Mar 2000) |
| pachymeningitis externa | Inflammation of the outer surface of the dura mater. Synonym: epidural meningitis, external meningitis. (05 Mar 2000) |
| vagina externa nervi optici | <anatomy, nerve> The outer sheath around the optic nerve, continuous with the dura mater. Synonym: vagina externa nervi optici, dural sheath of optic nerve. (05 Mar 2000) |
| vena iliaca externa | <anatomy, vein> A direct continuation of the femoral vein superior to the inguinal ligament, uniting with the internal iliac vein to form the common iliac vein. Synonym: vena iliaca externa. (05 Mar 2000) |
| vena jugularis externa | <anatomy, vein> Superficial vein formed inferior to the parotid gland by the junction of the posterior auricular vein and the retromandibular vein, and passes down the side of the neck crossing to the sternocleidomastoid muscle vertically to empty into the subclavian vein. Synonym: vena jugularis externa. (05 Mar 2000) |
| membrana intercostalis externa | The membrane that replaces the external intercostal muscle anteriorly between costal cartilages. Synonym: membrana intercostalis externa. (05 Mar 2000) |