| sagittal synostosis | <anatomy> A deformed condition of the skull, in which the vault is narrow, clongated, and more or less boat-shaped. Origin: Gr. A boat + head. Source: Websters Dictionary (01 Mar 1998) |
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| superior sagittal sinus | An unpaired dural venous sinus in the sagittal groove, beginning at the foramen caecum and terminating at the confluence of sinuses where it merges with the straight sinus; receives the superior cerebral veins and has lateral extensions, the lateral venous lacunae. Synonym: sinus sagittalis superior, superior longitudinal sinus. Tarsal sinus, a hollow or canal formed by the groove of the talus and the interosseous groove of the calcaneus which is occupied by the interosseous talocalcaneal ligament. Synonym: sinus tarsi, tarsal canal. (05 Mar 2000) |
| inferior sagittal sinus | An unpaired dural venous sinus in the lower margin of the falx cerebri, running parallel to the superior sagittal sinus and merging with the great cerebral vein to form the the straight sinus. Synonym: sinus sagittalis inferior, inferior longitudinal sinus. (05 Mar 2000) |
| left sagittal fissure | A sagittal groove on the undersurface of the liver formed by the fissura ligamenti teretis anteriorly and the fissura ligamenti venosi posteriorly. (05 Mar 2000) |
| acromion presentation | Transverse presentation with the shoulder as the presenting part. Synonym: acromion presentation. (05 Mar 2000) |
| antigen presentation | A cell that carries on its surface antigen bound to MCH Class I or Class II molecules and presents the antigen in this context to T-cells. Includes macrophages, endothelium, dendritic cells and Langerhans cells of the skin. See: MHC restriction, histocompatibility antigens. (18 Nov 1997) |
| breech presentation | Presentation of any part of the pelvic extremity of the foetus, the nates, knees, or feet; more properly only of the nates; frank breech presentation occurs when the foetus presents by the pelvic extremity; the thighs may be flexed and the legs extended over the anterior surfaces of the body; in (05 Mar 2000) |
| vertex presentation | See: cephalic presentation. (05 Mar 2000) |
| cephalic presentation | Presentation of any part of the foetal head, usually the upper and back part as a result of flexion such that the chin is in contact with the thorax in vertex presentation; there may be degrees of flexion so that the presenting part is the large fontanel in sincipital presentation, the brow in brow presentation, or the face in face presentation. Synonym: head presentation. (05 Mar 2000) |
| pelvic presentation | Presentation of any part of the pelvic extremity of the foetus, the nates, knees, or feet; more properly only of the nates; frank breech presentation occurs when the foetus presents by the pelvic extremity; the thighs may be flexed and the legs extended over the anterior surfaces of the body; in (05 Mar 2000) |
| clinical presentation | This refers to the typical physical signs or symptoms that are associated with a particular disease process. The proper interpretation of the clinical presentation often leads to a specific diagnosis. (27 Sep 1997) |
| placental presentation | <obstetrics> The anatomic positioning of the placenta over the cervical os (opening to the birth canal). This is an important cause of painless third trimester bleeding in the pregnant female. Many cases of placenta previa will require cesarean section delivery. (31 Dec 1997) |
| polar presentation | The presentation of either pole of the foetal oval; may be either a cephalic or breech presentation, or a longitudinal lie. (05 Mar 2000) |
| presentation | 1. <obstetrics> The relationship of the long axis of the foetus to that of the mother (also called lie) 2. The presenting part, i.e. That portion of the foetus which is touched by the examining finger through the cervix or during labour, is bounded by the girdle of resistance. Origin: L. Praesentatio (18 Nov 1997) |
| presentation, breech | Birth buttocks first. During a breech presentation, the baby's buttocks present first. (12 Dec 1998) |