| interauricular arc | A line carried over the cranium from the centre of one external auditory meatus to that of the other. Synonym: interauricular arc. (05 Mar 2000) |
|---|---|
| tungsten arc lamp | <apparatus> A lamp having highly compressed tungsten elements. (05 Mar 2000) |
| unipolar arc | <radiobiology> Arc between a metal surface and a plasma in contact with it. Such an arc requires only one electrode and is maintained by the thermal energy of the electrons. (09 Oct 1997) |
| flame arc | An arc between two impregnated electrodes that causes volatilization of the core with resultant flame. (05 Mar 2000) |
| longitudinal arc of skull | The line carried over the skull in the midline from the nasion to the opisthion. (05 Mar 2000) |
| specific dynamic action | The increase of heat production caused by the ingestion of food, especially of protein. (05 Mar 2000) |
| dynamic aorta | Abnormally marked pulsations of aorta. (05 Mar 2000) |
| dynamic compliance of lung | The value obtained when lung compliance is estimated during breathing by dividing the tidal volume by the difference in instantaneous transpulmonary pressures at the ends of the respiratory excursions, when flow in the airway is momentarily zero; this value deviates markedly from static compliance in patients in whom resistances and compliances are not uniform throughout the lung (i.e., uneven time constants). (05 Mar 2000) |
| dynamic computed tomography | Computed tomography with rapid injection of contrast medium, usually with sequential scans at only one or a few levels; used to enhance the vascular compartment. Synonym: dynamic CT. (05 Mar 2000) |
| dynamic CT | Computed tomography with rapid injection of contrast medium, usually with sequential scans at only one or a few levels; used to enhance the vascular compartment. Synonym: dynamic CT. (05 Mar 2000) |
| dynamic demography | A study of the functioning of a community, including statistical records. (05 Mar 2000) |
| dynamic disease | A physical disorder with no known or detectable organic basis to explain the symptoms. See: behaviour disorder, neurosis. Synonym: dynamic disease, functional disease, functional illness. (05 Mar 2000) |
| dynamic equilibrium | Balance A condition in which no further net change is occuring in a system, and free energy is minimimal. (09 Oct 1997) |
| dynamic focusing | <microscopy> An automatic focusing adjustment of the electron beam in high-quality cathode-ray or video image pickup tubes. The beam is made to land with the properly shaped minimum-sized spot regardless of its position in the raster scan (05 Aug 1998) |
| dynamic force | <radiobiology> Typically defined as the ability to do work. Power is the rate at which work is done, or the rate at which energy is changed. Work characterises the degree to which the properties of a substance are transformed. Energy exists in many forms, which can be converted from one to another in various ways. Examples include: gravitational energy, electrical energy, magnetic and electric field energy, atomic binding energy (a form of electrical energy really), nuclear binding energy, chemical energy (another form of electrical energy), in addition to these forms of potential energy there are also kinetic energy (energy due to motion), and thermal energy (heat, a form of kinetic energy where the motion is due to thermal vibrations/motions), and so on. (09 Oct 1997) |