| A1 | aortic first sound |
|---|---|
| A2 | aortic second sound |
| A2-OS | aortic second sound, opening snap |
| ACS | acrocallosal syndrome; acrocephalosyndactyly; acute chest syndrome; acute confusional state; Alcon C... |
| AES | acetone-extracted serum; American Electroencephalographic Society; American Encephalographic Society... |
| respiratory acidosis | <biochemistry> A metabolic derangement of acid-base balance where the blood pH is abnormally low. Causes include haemorrhagic shock, cardiogenic shock, severe dehydration, sepsis, toxic ingestion (for example isopropyl alcohol, methanol), alcoholic ketoacidosis, lactic acidosis, renal failure and diabetic ketoacidosis. Respiratory acidosis will occur if the lungs are not ventilating properly resulting in an excess of carbon dioxide in the body. (25 Jun 1999) |
|---|---|
| respiratory airway | That part of the airway where interchange of gases occurs; it includes respiratory bronchioles, alveolar ducts, sacs, and alveoli. (05 Mar 2000) |
| respiratory alkalosis | The alkalosis resulting from abnormal loss of CO2 produced by hyperventilation, either active or passive, with concomitant reduction in arterial plasma bicarbonate concentration. See: compensated alkalosis. Synonym: acapnial alkalosis. (05 Mar 2000) |
| respiratory apparatus | The organs that are involved in breathing. These include the nose, throat, larynx, trachea, bronchi, and lungs. (12 Dec 1998) |
| respiratory arrhythmia | Phasic sinus arrhythmia or any other rhythm fluctuation induced by respiratory fluctuation. (05 Mar 2000) |
| respiratory ataxia | Completely irregular breathing pattern, with continually variable rate and depth of breathing; results from lesions in the respiratory centres in the brainstem, extending from the dorsomedial medulla caudally to the obex. Synonym: ataxic breathing, Biot's breathing, respiratory ataxia. (05 Mar 2000) |
| respiratory bronchioles | The smallest bronchioles (0.5 mm in diameter) that connect the terminal bronchioles to alveolar ducts; alveoli rise from part of the wall. Synonym: bronchioli respiratorii. (05 Mar 2000) |
| respiratory burst | <biochemistry> Response of phagocytes to particles (particularly if opsonise d) and to agonists such as formyl peptides and phorbol esters, an enhanced uptake of oxygen leads to the production, by an NADH dependent system, of hydrogen peroxide, superoxide anions and hydroxyl radicals, all of which play a part in bactericidal activity. Defects in the metabolic burst, as in chronic granulomatous disease, predispose to infection particularly with catalase positive bacteria and are usually fatal in childhood. (27 Jun 1999) |
| respiratory capacity | <chest medicine, physiology> The volume of gas that can be expelled from the lungs from a position of full inspiration, with no limit to the duration of expiration, it is equal to the inspiratory capacity plus the expiratory reserve volume. (11 Nov 1997) |
| respiratory care unit | The hospital unit in which patients with respiratory conditions requiring special attention receive intensive medical care and surveillance. (12 Dec 1998) |
| respiratory centre | The region in the medulla oblongata concerned with integrating afferent information to determine the signals to the respiratory muscles; the inspiratory and expiratory centre's considered together. (05 Mar 2000) |
| respiratory chain | The mitochondrial electron transport chain. (18 Nov 1997) |
| respiratory circulation | The mechanisms of pulmonary circulation coordinated with the heart and systemic circulation. It involves the flow or interruption of the flow of blood to the lungs as it affects respiration. Pulmonary circulation, a circulatory concept, emphasizes the passage of blood from the right to the left heart through the lungs. Respiratory circulation coordinates this with heart action, systemic circulation, and breathing. (12 Dec 1998) |
| respiratory coefficient | <physiology> Molar ratio of carbon dioxide production to oxygen consumption. (18 Nov 1997) |
| respiratory dead space | That portion of the respiratory tract, from the nose and mouth to the terminal bronchioles, in which exchange of oxygen and carbon dioxide does not occur (anatomical dead space), together with the space in alveoli occupied by air that does not participate in oxygen-carbon dioxide exchange (physiologic dead space). It reflects the nonuniformity of ventilation and perfusion in the lung. (12 Dec 1998) |