| conduction | <physics, physiology> The transfer of sound waves, heat, nervous impulses or electricity. Origin: L. Conductio (18 Nov 1997) |
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| conduction anaesthesia | Regional anaesthesia in which local anaesthetic solution is injected about nerves to inhibit nerve transmission; includes spinal, epidural, nerve block, and field block anaesthesia, but not local or topical anaesthesia. Synonym: block anaesthesia. (05 Mar 2000) |
| conduction analgesia | Use of local anaesthetic solution(s) to produce circumscribed areas of loss of sensation; a generic term including conduction, nerve block, spinal, epidural, field block, infiltration, and topical anaesthesia. Synonym: conduction analgesia. (05 Mar 2000) |
| conduction aphasia | A form of aphasia in which the patient understands spoken and written words, is aware of his deficit, and can speak and write, but skips or repeats words, or substitutes one word for another (paraphasia);word repetition is severely impaired. The responsible lesion is in the associate tracks connecting the various language centres. Synonym: associative aphasia. (05 Mar 2000) |
| conduction block | Failure of impulse transmission at some point along a nerve, although conduction along the segments proximal and distal to it are unaffected. Clinically, most often caused by an area of focal demyelination; when caused by focal trauma, called neurapraxia. (05 Mar 2000) |
| aberrant ventricular conduction | Abnormal intraventricular conduction of a supraventricular beat, especially where surrounding beats are normally conducted. Synonym: ventricular aberration. (05 Mar 2000) |
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| accelerated conduction | Any pathologically increased speed of conduction; usually occurs between the atrium and ventricles as in the Wolff-Parkinson-White and Lown-Ganong-Levine syndromes; such accelerated pathways provide the bases for particular forms of reentry tachycardia. (05 Mar 2000) |
| A-H conduction time | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| air conduction | In relation to hearing, the transmission of sound to the inner ear through the external auditory canal and the structures of the middle ear. (05 Mar 2000) |
| anomalous conduction | Conduction of cardiac electrical impulses through any abnormal pathway. (05 Mar 2000) |
| antegrade conduction | Conduction in the expected normal direction between any cardiac structures. Synonym: antegrade conduction, forward conduction, orthograde conduction. (05 Mar 2000) |
| anterograde conduction | Conduction in the expected normal direction between any cardiac structures. Synonym: antegrade conduction, forward conduction, orthograde conduction. (05 Mar 2000) |
| aphasia, conduction | A type of fluent aphasia in which there is normal comprehension of spoken language but words are repeated incorrectly. It results from a lesion of the arcuate fasciculus connecting broca's and wernicke's areas. Like patients with wernicke's aphasia (aphasia, wernicke), patients with conduction aphasia are fluent but have many paraphasic errors (incorrect words or sounds substituted for correct ones). The degree of fluency is less than that in wernicke's aphasia, but comprehension is good. (12 Dec 1998) |
| atrioventricular conduction | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| atrioventricular conduction abnormalities | <cardiology, physiology> Any condition which involves abnormal (blocked, delayed or aberrant) electrical conduction through the atrioventricular node (for example atrioventricular block). Some medications may precipitate atrioventricular conduction abnormalities. (02 Jan 1998) |
| avalanche conduction | <physiology> The discharge of an impulse from a neuron into a large number of neurons of the same physiologic system. This produces an amplification effect, thus producing a very large amount of nervous energy for a given stimulus. (05 Mar 2000) |
| A-V conduction | Forward conduction of the cardiac impulse from atria to ventricles via the A-V node or any bypass tract, represented in the electrocardiogram by the P-R interval. P-H conduction time is from the onset of the P wave to the first high frequency component of the His bundle electrogram (normally 119 ± 38 msec); A-H conduction time is from the onset of the first high frequency component of the atrial electrogram to the first high frequency component of the His bundle electrogram (normally 92 ± 38 msec); P-A conduction time is from the onset of the P wave to the onset of the atrial electrogram (normally 27 ± 18 msec). (05 Mar 2000) |
| A-V conduction abnormalities | <cardiology, physiology> Any condition which involves abnormal (blocked, delayed or aberrant) electrical conduction through the atrioventricular node (for example atrioventricular block). Some medications may precipitate atrioventricular conduction abnormalities. (02 Jan 1998) |
| bone conduction | The conduction of sound to the inner ear through the bones of the skull. (12 Dec 1998) |
| P-A conduction time | See: atrioventricular conduction. (05 Mar 2000) |