| internal spermatic artery | <anatomy, artery> Origin, aorta; branches, ureteral, cremasteric, epididymal; distribution, testicle and parts designated by names of branches; anastomoses, branches of renal, inferior epigastric, deferential. Synonym: arteria testicularis, arteria spermatica interna, internal spermatic artery. (05 Mar 2000) |
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| internal spermatic fascia | The inner covering of the spermatic cord, continuous above the deep inguinal ring with fascia transversalis. Synonym: fascia spermatica interna, infundibuliform fascia, tunica vaginalis communis. (05 Mar 2000) |
| internal sphincter muscle of anus | <anatomy> A smooth muscle ring, formed by an increase of the circular fibres of the rectum, situated at the upper end of the anal canal, internal to the outer voluntary external anal sphincter. This sphincter is maximally-contracted when the rectal ampulla is at rest -empty or relaxed to accommodate a distending faecal mass. It is inhibited with filling of the ampulla, increased distension and peristalsis. Synonym: musculus sphincter ani internus, internal sphincter muscle of anus. (05 Mar 2000) |
| internal spiral sulcus | A concavity in the floor of the cochlear duct formed by the overhanging labium vestibulare. Synonym: sulcus spiralis internus. (05 Mar 2000) |
| internal squint | Cross-eyed. (27 Sep 1997) |
| internal strabismus | An obsolete term for esotropia (05 Mar 2000) |
| internal surface | The internal concave surface of either the frontal or the parietal bone. Synonym: facies interna. (05 Mar 2000) |
| internal surface of frontal bone | The surface of the frontal bone that contributes to the wall of the cranial cavity. Synonym: facies interna ossis frontalis. (05 Mar 2000) |
| internal surface of parietal bone | The concave surface of the parietal bone forming part of the wall of the cranial cavity. Synonym: facies interna ossis parietalis. (05 Mar 2000) |
| internal thoracic artery | <anatomy, artery> Origin, subclavian; branches, pericardiacophrenic, anterior intercostal, sternal, mediastinal, thymic, bronchial, muscular, and perforating branches, and bifurcates into the musculophrenic and superior epigastric. Synonym: arteria thoracica interna, arteria mammaria interna, internal mammary artery. (05 Mar 2000) |
| internal thoracic vein | <anatomy, vein> Venae comitantes of each artery of the same name, fusing into one at the upper part of the thorax and emptying into the brachiocephalic vein of the same side; receive drainage of anterior chest wall. Synonym: vena thoracica interna. (05 Mar 2000) |
| internal traction | A pulling force created by using one of the cranial bones, above the point of fracture, for anchorage. (05 Mar 2000) |
| internal urethral opening | The internal opening or orifice of the urethra, at the anterior and inferior angle of the trigone. Synonym: ostium urethrae internum, internal urethral opening. (05 Mar 2000) |
| internal urethral orifice | The internal opening or orifice of the urethra, at the anterior and inferior angle of the trigone. Synonym: ostium urethrae internum, internal urethral opening. (05 Mar 2000) |
| internal urethral sphincter | The complete collar of smooth muscle cells of the neck of the urinary bladder which extend distally to surround the preprostatic sportion of the male urethra. There is not a comparable structure in the neck of the femoral bladder; the internal urethral sphincter may exist to prevent reflux of semen into bladder. Synonym: annulus urethralis, internal urethral sphincter, musculus sphincter vesicae, preprostate urethral sphincter, proximal urethral sphincter, sphincter muscle of urinary bladder. (05 Mar 2000) |