| TAA | thioacetamide; thoracic aortic aneurysm; total ankle arthroplasty; transverse aortic arch; tumor-ass... |
|---|---|
| ABR | Absolute Bed Rest |
| ABO | abortion; absent bed occupancy; American Board of Orthodontists; blood group system consisting of gr... |
| ABR | abortus Bang ring [test]; absolute bed rest; auditory brainstem response |
| ABS | abdominal surgery; acute brain syndrome; Adaptive Behavior Scale; admitting blood sugar; adult bovin... |
| aortic atresia | Congenital absence of the normal valvular orifice into the aorta. (05 Mar 2000) |
|---|---|
| aortic bodies | Small clusters of chemoreceptive and supporting cells located near the aortic arch, the pulmonary arteries, and the coronary arteries. The aortic bodies sense pH, carbon dioxide, and oxygen concentrations in the blood and participate in the control of respiration. (12 Dec 1998) |
| aortic body tumour | Aortic body, carotid body, chemoreceptor, or glomus jugulare tumour; nonchromaffin paraganglioma; receptoma; a relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the carotid body, glomus jugulare, and aortic bodies; consisting histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. Compare: paraganglioma. Synonym: aortic body tumour, carotid body tumour, chemoreceptor tumour, glomus jugulare tumour, nonchromaffin paraganglioma. Origin: chemo-+ G. Dektes, receiver, fr. Dechomai, to receive, + -oma, tumour (05 Mar 2000) |
| aortic bulb | The dilated first part of the aorta containing the aortic semilunar valves and the aortic sinuses. Synonym: bulbus aortae, arterial bulb. (05 Mar 2000) |
| aortic coarctation | <radiology> most frequent cause of PVH and congestive heart failure in 2nd and 3rd weeks of life associated with, bicuspid aortic valve (50-80%), calcific aortic stenosis (due to bicuspid valve), patent ductus arteriosus or VSD (in most) see also: abdominal aortic coarctation (12 Dec 1998) |
| aortic curtain | An intertrigonal sheet of fibrous tissue between the aortic annulus and the anterior leaflet of the mitral valve. (05 Mar 2000) |
| aortic dissection | A pathologic process, characterised by splitting of the media layer of the aorta, which leads to formation of a dissecting aneurysm. Classified according to location as follows: type I involves the ascending aorta, transverse arch, and distal aorta; type II is confined to the ascending aorta; type III extends distally in the descending aorta. (05 Mar 2000) |
| aortic dissection: aetiology | <radiology> Usually degenerative, due to aging, increased risk: hypertension, bicuspic aortic valve, aortic coarctation, pregnancy, connective tissue disorder (Marfan, Ehlers-Danlos), skeletal abnormalities (scoliosis, pectus), mycotic aneurysm, Takayasu (giant cell) arteritis, aortic laceration see also: classification (12 Dec 1998) |
| aortic dissection: classification | <radiology> DeBakey: I ascending aorta to arch with or without descending aorta (30%), II ascending aorta only (20%), III descending aorta to thoracic aorta (50%), Stanford: A involvement of ascending aorta (regardless of origin), B aortic arch and distal aorta see also: aetiology mnemomics: 1 A.D. (DeBakey), A = Ascending (12 Dec 1998) |
| aortic dwarfism | Underdevelopment of physical stature associated with severe aortic stenosis. (05 Mar 2000) |
| aortic facies | The pale sallow complexion of one suffering from incompetence of the aortic valve. (05 Mar 2000) |
| aortic foramen | The opening in the diaphragm bounded by the two crura, the vertebral column, and the median arcuate ligament, through which pass the aorta and thoracic duct. Synonym: hiatus aorticus, aortic foramen, aortic opening. (05 Mar 2000) |
| aortic hiatus | The opening in the diaphragm bounded by the two crura, the vertebral column, and the median arcuate ligament, through which pass the aorta and thoracic duct. Synonym: hiatus aorticus, aortic foramen, aortic opening. (05 Mar 2000) |
| aortic incompetence | Defective closure of the aortic valve permitting regurgitation into the left ventricle during diastole. (05 Mar 2000) |
| aortic insufficiency | A congenital or acquired heart valve abnormality that results in the abnormal back flow of blood in the aorta, through an incompetent aortic valve and into the left ventricle. Chronic aortic insufficiency leads to enlargement of the left ventricle and pulmonary congestion. If left uncorrected, congestive heart failure will result. Aortic valve replacement is eventually necessary in most cases of significant valvular incompetence. (27 Sep 1997) |