| total end-systolic diameter | Cross sectional diameter of the left ventricle including the septum and posterior wall thicknesses in systole. (05 Mar 2000) |
|---|---|
| trachelobregmatic diameter | The diameter of the foetal head from the middle of the anterior fontanelle to the neck. (05 Mar 2000) |
| transverse diameter | The transverse diameter of the pelvic inlet, measured between the terminal lines. Synonym: diameter transversa. (05 Mar 2000) |
| external conjugate diameter | The distance in a straight line between the depression under the last spinous process of the lumbar vertebrae and the upper edge of the pubic symphysis. Synonym: Baudelocque's diameter, external conjugate diameter. (05 Mar 2000) |
| zygomatic diameter | The extreme breadth of the skull at the zygomatic arches. (05 Mar 2000) |
| abdominal sac | The part of the embryonic celom that becomes the abdominal cavity. (05 Mar 2000) |
| air sac | <zoology> Thin-walled sacs or spaces which function as a part of the respiratory system in birds, fishes, insects, and mammals. The sacs are filled with air and connected with the air passages of the lungs; an air cell. Source: Websters Dictionary (04 Jul 1999) |
| allantoic sac | The dilated distal portion of the allantois; it forms part of the placenta in many mammals. (05 Mar 2000) |
| alveolar sac | Terminal dilation of the alveolar ducts that give rise to alveoli in the lung; a small air chamber in the pulmonary tissue from which the pulmonary alveoli project like bays and into which an alveolar duct opens; in birds, air-containing extensions of bronchi that connect with bone cavities. Synonym: sacculus alveolaris, air sac. (05 Mar 2000) |
| amniotic sac | <anatomy, obstetrics> Sac, enclosing the embryo of amniote vertebrates, that provides a fluid environment to prevent dehydration during development of land based animals. See: amnion. (18 Nov 1997) |
| anal sac | A vesicular cutaneous invagination opening by a duct on each side of the anal canal in carnivores (best developed in skunks, but absent in some bears, the raccoon, kinkajou, coati, and sea otter), each lying between the external and internal anal sphincter muscles, which aid in emptying the contents. The sac stores odouriferous scent markers produced by glands that line its wall or duct; frequently the sac becomes impacted in the dog or cat, requiring manual emptying. (05 Mar 2000) |
| aneurysmal sac | The dilated wall of an artery in a saccular aneurysm. (05 Mar 2000) |
| aortic sac | In mammalian embryos, the endothelially lined dilation just distal to the truncus arteriosus; it is the primordial vascular channel from which the aortic arches arise and is homologous to the ventral aorta of gill-bearing vertebrates. (05 Mar 2000) |
| rami laterales ramorum dorsalium nervorum cervicalium/thoracalium/lumbalium/sac | Lateral branch of dorsal primary rami of spinal nerves. See: lateral branches. (05 Mar 2000) |
| gestation sac | The gestation sac is the fluid-filled sac in which the foetus develops, visible with an ultrasound exam. (09 Oct 1997) |