| external spermatic fascia | The outer fascial covering of the spermatic cord; it is continuous at the superficial inguinal ring with the fascia covering the external oblique muscle. See: aponeurosis of external abdominal oblique muscle. Synonym: fascia spermatica externa. (05 Mar 2000) |
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| external sphincter muscle of anus | 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 sphincterotomy | Transurethral incision of external urethral sphincter. (05 Mar 2000) |
| external spiral sulcus | A concavity in the outer wall of the cochlear duct between the prominentia spiralis and the spiral organ. Synonym: sulcus spiralis externus. (05 Mar 2000) |
| external squint | <clinical sign> The outward or temporal deviation of an eye. (27 Sep 1997) |
| external strabismus | An obsolete term for exotropia. (05 Mar 2000) |
| external surface | The outer convex surface of either the frontal or the parietal bone. Synonym: facies externa. (05 Mar 2000) |
| external surface of frontal bone | The convex outer surface of the frontal bone. Synonym: facies externa ossis frontalis. (05 Mar 2000) |
| external surface of parietal bone | The convex outer surface of the parietal bone. Synonym: facies externa ossis parietalis. (05 Mar 2000) |
| external traction | A pulling force created by using fixed anchorage (e.g., a headcap or bed frame) outside the oral cavity; principally used in the management of midfacial fractures. (05 Mar 2000) |
| external urethral orifice | The slitlike opening of the urethra in the glans penis, the external orifice of the urethra (in the female) in the vestibule, usually upon a slight elevation, the papilla urethrae. Synonym: ostium urethrae externum, external opening of urethra, meatus urinarius, orificium urethrae externum. (05 Mar 2000) |
| external urethral sphincter | Origin, ramus of pubis; insertion, with fellow in median raphe behind and in front of urethra; action, constricts membranous urethra; nerve supply, pudendal. Synonym: musculus sphincter urethrae, external urethral sphincter, Guthrie's muscle, musculus compressor urethrae, musculus constrictor urethrae, musculus sphincter urethrae membranaceae, sphincter muscle of urethra, Wilson's muscle. (05 Mar 2000) |
| external wall of cochlear duct | The wall that faces the outer side of the cochlea. Synonym: paries externus ductus cochlearis. (05 Mar 2000) |
| abducens nerve | <anatomy, nerve> The 6th cranial nerve. The abducens nerve originates in the abducens nucleus of the pons and sends motor fibres to the lateral rectus muscles of the eye. Damage to the nerve or its nucleus disrupts horizontal eye movement control. (12 Dec 1998) |
| abducent nerve | <anatomy> The abducent nerve enervates a muscle which moves the eyeball. Lesions of the sixth cranial nerve result in deviation of the eyeball outward and double vision. Synonym: cranial nerve VI. (27 Sep 1997) |