| LRA | low right atrium |
|---|---|
| LSRA | low septal right atrium |
| RA | radioactive; ragocyte; ragweed antigen; rapidly adapting [receptors]; reactive arthritis; reciprocal... |
| RAD | radial artery catheter; radiation absorbed dose; radical; radiography or radiographic; reactive airw... |
| AD | 1) Alveolar Duct 2) Autosomal Dominant 3) Auris Dextra; Ri... |
| alveolar bone loss | The resorption of bone in the supporting structures of the maxilla or mandible as a result of periodontal disease. (12 Dec 1998) |
|---|---|
| alveolar border | The most occlusal edge of the alveolar bone. Synonym: alveolar process. (05 Mar 2000) |
| alveolar canals | Canals in the body of the maxilla that transmit nerves and vessels from the alveolar foramina to the maxillary teeth. Synonym: canales alveolares, alveolodental canals, dental canals. (05 Mar 2000) |
| alveolar cell | Cell of the air sac of the lung. (18 Nov 1997) |
| alveolar cell carcinoma | <tumour> A carcinoma, thought to be derived from epithelium of terminal bronchioles, in which the neoplastic tissue extends along the alveolar walls and grows in small masses within the alveoli; involvement may be uniformly diffuse and massive, or nodular, or lobular; microscopically, the neoplastic cells are cuboidal or columnar and form papillary structures; mucin may be demonstrated in some of the cells and in the material in the alveoli, which also includes denuded cells; metastases in regional lymph nodes, and even in more distant sites, are known to occur, but are infrequent. Synonym: alveolar cell carcinoma, bronchiolar adenocarcinoma, bronchiolo-alveolar carcinoma, bronchioloalveolar adenocarcinoma. (05 Mar 2000) |
| alveolar crest | The portion of the alveolar bone extending beyond the periphery of the socket, lying interproximally, the top of the residual alveolar bone. (05 Mar 2000) |
| alveolar dead space | The difference between physiologic dead space and anatomical dead space; it represents that part of the physiologic dead space resulting from ventilation of relatively underperfused or nonperfused alveoli; it differs specifically in being placed so as to fill and empty in parallel with functional alveoli, rather than being interposed in the conducting tubes between functional alveoli and the external environment. (05 Mar 2000) |
| alveolar duct | The part of the respiratory passages distal to the respiratory bronchiole; from it arise alveolar sacs and alveoli, the smallest of the intralobular duct's in the mammary gland, into which the secretory alveoli open. Synonym: ductulus alveolaris. (05 Mar 2000) |
| alveolar duct emphysema | Emphysema in which the primary involvement is in the alveolar ducts and respiratory bronchioles, as opposed to panacinar emphysema. (05 Mar 2000) |
| alveolar foramina | Openings of the posterior dental canals on the infratemporal surface of the maxilla. Synonym: foramina alveolaria. (05 Mar 2000) |
| alveolar gas | The gas in the pulmonary alveoli, where O2-CO2 exchange with pulmonary capillary blood occurs. Synonym: alveolar air. (05 Mar 2000) |
| alveolar gas equation | The equation defining the steady state relation of the alveolar oxygen pressure to the barometric pressure, inspired gas composition, alveolar carbon dioxide pressure, and respiratory exchange ratio; the equation is used in various forms depending upon which simplifying assumptions are acceptable for different applications. (05 Mar 2000) |
| alveolar gingiva | Gingival tissue applied to the alveolar bone. (05 Mar 2000) |
| alveolar gland | A gland in which the secretory unit(s) has a saclike form and an obvious lumen; e.g., the active mammary gland. (05 Mar 2000) |
| alveolar hydatid cyst | A hydatid cyst of a multiloculate type, usually in the liver, caused by Echinococcus multilocularis, adults of which are in foxes; larvae (alveolar hydatid) are found chiefly in microtine rodents, but also among humans such as trappers and others handling pelts of infected foxes and other carnivores; growth is by exogenous budding and is not limited by an outer laminated membrane as in the hydatid cyst from E. Granulosus; necrosis, cavitation, contiguous spread, and death usually ensue. Synonym: multilocular hydatid cyst, multiloculate hydatid cyst. (05 Mar 2000) |