| dynamic psychology | A psychologic approach that concerns itself with the causes of behaviour. (05 Mar 2000) |
|---|---|
| dynamic psychotherapy | Psychotherapy utilizing freudian principles. See: psychoanalysis. Synonym: dynamic psychotherapy. (05 Mar 2000) |
| dynamic range | <microscopy> In video and other electronic equipment and in photographic emulsions, the ratio of the maximum to minimum signal levels that introduce no more than acceptable levels of signal amplitude distortions. (05 Aug 1998) |
| dynamic refraction | Refraction of the eye during accommodation. (05 Mar 2000) |
| dynamic relations | Relative movements between two objects, e.g., the relationship of the mandible to the maxillae. (05 Mar 2000) |
| dynamic school | A group of theorists founded by Stahl, who professed the belief that all vital action is the result of an internal force independent of anything external to the body. (05 Mar 2000) |
| dynamic splint | A splint utilizing springs or elastic bands that aids in movements initiated by the patient by controlling the plane and range of motion. Synonym: active splint, functional splint. (05 Mar 2000) |
| dynamic viscosity | The internal or molecular frictional resistance of a fluid by Newton's law of viscosity as the ratio of the applied force per unit area to the relative velocity of adjacent fluid layers (produced by the force). (05 Mar 2000) |
| instrascene dynamic range | <microscopy> The greatest ratio of highlight to shadow brightness to within a single scene that a video camera (tube) can handle usefully. Contrast with the usable light range of a camera, which is considerably greater than the instrascene dynamic range. See: illumination, Kohler. (05 Aug 1998) |
| alveolocapillary block | The presence of material that impairs the diffusion of gases between the air in the alveolar spaces and the blood in alveolar capillaries; block can be caused by oedema, cellular infiltration, fibrosis, or tumour, and results in undersaturation of peripheral arterial blood with oxygen. (05 Mar 2000) |
| anterograde block | Conduction block of an impulse traveling anywhere in its ordinary direction, for example, from the sinoatrial node toward the ventricular myocardium. (05 Mar 2000) |
| arborization block | Intraventricular block supposedly due to widespread blockage in the Purkinje ramifications and manifested in the electrocardiogram by a pattern similar to bundle-branch block but with complexes of low amplitude. (05 Mar 2000) |
| atrioventricular block | <cardiology> A conduction disturbance that results in the inappropriate delay (or complete inability) of a electrical impulse, generated in the atria, to reach the ventricles (via the atrioventricular node). Clinical types are divided into first (nonserious), second and third degree (most serious). Some drugs may precipitate atrioventricular block (for example clonidine, methyldopa, verapamil). A permanent pacemaker may be required for a third degree (complete) heart block. (02 Jan 1998) |
| autonomic nerve block | Interruption of sympathetic pathways, by local injection of an anaesthetic agent, at any of four levels: peripheral nerve block, sympathetic ganglion block, extradural block, and subarachnoid block. (12 Dec 1998) |
| A-V block | <cardiology> A conduction disturbance that results in the inappropriate delay (or complete inability) of a electrical impulse, generated in the atria, to reach the ventricles (via the atrioventricular node). Clinical types are divided into first (nonserious), second and third degree (most serious). Some drugs may precipitate atrioventricular block (for example clonidine, methyldopa, verapamil). A permanent pacemaker may be required for a third degree (complete) heart block. (02 Jan 1998) |