D factor
| lower nodal extrasystole | An obsolete term for a nodal extrasystole supposed to arise from the lower part of the A-V node, recognised in the electrocardiogram by the retrograde P wave that follows the QRS complex. (05 Mar 2000) |
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| lower oesophageal sphincter | <anatomy> A muscular sphincter located at the junction of the oesophagus and the stomach. On closure the lower oesophageal sphincter prevents the back wash (reflux) of stomach acid into the oesophagus where it may damage the mucosa. See: gastrooesophageal reflux disease. (16 Mar 1998) |
| lower respiratory tract | <anatomy> The trachea, bronchi, and lungs. (09 Oct 1997) |
| lower respiratory tract smear | A group of cytologic specimens containing material from the lower respiratory tract and consisting mainly of sputum (spontaneous, induced) and material obtained at bronchoscopy (aspirated, lavaged, brushed); used for cytologic study of cancer and other diseases of the lungs. Synonym: bronchoscopic smear, sputum smear. (05 Mar 2000) |
| Lower, Richard | <person> English anatomist and physiologist, 1631-1691. See: Lower's ring, Lower's tubercle. (05 Mar 2000) |
| lower segment cesarian section | A Cesarian section in which the surgical incision (cut) is made in the lower segment of the uterus. (12 Dec 1998) |
| Lower's ring | One of four fibrous rings that surround atrioventricular and arterial orifices of the heart, providing attachment for the valve leaflets and maintaining patency of the orifice. As part of the fibrous skeleton of the heart, the fibrous rings also provide origin and insertion for the myocardium. Synonym: annulus fibrosus cordis, annulus fibrosus, coronary tendon, fibrous ring, Lower's ring. (05 Mar 2000) |
| Lower's tubercle | The slight projection on the wall of the right atrium between the orifices of the venae cavae. Synonym: tuberculum intervenosum, Lower's tubercle. (05 Mar 2000) |
| lower uterine segment | The inferior portion or isthmus of the uterus, the lower extremity of which joins with the cervical canal and, during pregnancy, expands to become the lower part of the uterine cavity. (05 Mar 2000) |
| lower uterine segment cesarean section | A cesarean section in which the uterus is entered in its lower segment by a transperitoneal approach. (05 Mar 2000) |
| aditus pelvis | The upper opening of the true pelvis, bounded anteriorly by the pubic symphysis and the pubic crest on either side, laterally by the iliopectineal lines, and posteriorly by the promontory of the sacrum. Synonym: apertura pelvis superior, aditus pelvis, first parallel pelvic plane, pelvic brim, pelvic inlet, pelvic plane of inlet, plane of inlet. (05 Mar 2000) |
| android pelvis | A masculine or funnel-shaped pelvis. (05 Mar 2000) |
| anthropoid pelvis | An apelike pelvis, with a long anteroposterior diameter and a narrow transverse diameter. (05 Mar 2000) |
| apertura pelvis inferior | The lower opening of the true pelvis, bounded anteriorly by the pubic arch, laterally by the rami of the ischium and the sacrotuberous ligament on either side, and posteriorly by these ligaments and the tip of the coccyx. Synonym: apertura pelvis inferior, apertura pelvis minoris, fourth parallel pelvic plane, pelvic outlet, pelvic plane of outlet, plane of outlet. (05 Mar 2000) |
| apertura pelvis minoris | The lower opening of the true pelvis, bounded anteriorly by the pubic arch, laterally by the rami of the ischium and the sacrotuberous ligament on either side, and posteriorly by these ligaments and the tip of the coccyx. Synonym: apertura pelvis inferior, apertura pelvis minoris, fourth parallel pelvic plane, pelvic outlet, pelvic plane of outlet, plane of outlet. (05 Mar 2000) |