| crista sacralis | One of three rough irregular ridges on the posterior surface of the sacrum; median sacral crest; lateral sacral crests. Synonym: crista sacralis. (05 Mar 2000) |
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| hiatus sacralis | A normally-occurring gap at the lower end of the sacrum, exposing the vertebral canal, due to failure of the laminae of the last sacral segment to coalesce. It is closed by the sacrococcygeal ligament, and provides cannular access to the sacral epidural space for administration of anaesthetics (caudal nerve blocks). Synonym: hiatus sacralis. (05 Mar 2000) |
| hiatus totalis sacralis | Developmental clefting in all sacral vertebrae; may also involve adjacent lumbar vertebrae. (05 Mar 2000) |
| tuberositas sacralis | A rough prominence on the lateral surface of the sacrum posterior to the auricular surface for attachment of posterior sacroiliac ligaments. Synonym: tuberositas sacralis. (05 Mar 2000) |
| flexura sacralis recti | The anteroposterior curve with concavity anteriorward of the first portion of the rectum. Synonym: flexura sacralis recti. (05 Mar 2000) |
| apertura mediana ventriculi quarti | The large midline opening in the posterior inferior part of the roof of the fourth ventricle, connecting the ventricle with the cerebellomedullary cistern. Synonym: apertura mediana ventriculi quarti, arachnoid foramen, Magendie's foramen, median aperture of the fourth ventricle. (05 Mar 2000) |
| arteria mediana | <anatomy, artery> Origin, anterior interosseous; distribution, accompanies median nerve to palm; anastomoses, branches of superficial palmar arch. Synonym: arteria comitans nervi mediani, arteria mediana. (05 Mar 2000) |
| articulatio atlantoaxialis mediana | A pivot synovial joint between the dens of the axis and the ring formed by the anterior arch and the transverse ligament of the atlas. Synonym: articulatio atlantoaxialis mediana, Cruveilhier's joint, middle atlantoepistrophic joint. (05 Mar 2000) |
| plica glossoepiglottica mediana | <anatomy> A fold of mucous membrane in the midline that extends from the back of the tongue to the epiglottis, forming the medial boundary of the epiglottic valleculae. Synonym: plica glossoepiglottica mediana, frenulum epiglottidis, middle glossoepiglottic fold. (05 Mar 2000) |
| plica umbilicalis mediana | A fold of peritoneum on the anterior wall of the abdomen covering the urachus, or remains of the allantoic stalk. Synonym: plica umbilicalis mediana, middle umbilical fold, plica umbilicalis media, plica urachi, urachal fold. (05 Mar 2000) |
| sutura palatina mediana | Line of union between the horizontal plates of the palatine bones, continuing the intermaxillary suture posteriorly. Synonym: sutura palatina mediana. (05 Mar 2000) |
| diameter mediana | Distance from the promontory of the sacrum to the upper posterior edge of the pubic symphysis. Synonym: anteroposterior diameter of the pelvic inlet, conjugata vera, conjugate axis, conjugate diameter of pelvic inlet, diameter mediana, internal conjugate, true conjugate. (05 Mar 2000) |
| eminentia mediana | <anatomy> Raised area on the infundibular hypothalamus at the floor of the third ventricle of the brain which contains the primary capillary network of the hypophyseal portal system. (12 Dec 1998) |
| fissura mediana anterior medullae oblongatae | The longitudinal groove in the midline of the anterior aspect of the medulla oblongata; it is the medullary equivalent of the anterior median fissure of the spinal cord and ends at the foramen caecum posterius; its caudal part is obliterated by the decussation of the pyramids. Synonym: fissura mediana anterior medullae oblongatae, anteromedian groove. (05 Mar 2000) |
| fissura mediana anterior medullae spinalis | A deep median fissure on the anterior surface of the spinal cord. Synonym: fissura mediana anterior medullae spinalis, anteromedian groove, sulcus ventralis. (05 Mar 2000) |