| unipolar leads | Those in which the exploring electrode is on the chest in the vicinity of the heart or on one of the limbs, while the other or indifferent electrode is the central terminal. (05 Mar 2000) |
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| unipolar | 1. <physics> Having, or acting by means of, one pole only. 2. <anatomy> Having but one pole or process; applied to those ganglionic nerve cells which have but one radiating process; opposed to multipolar. <physics> Unipolar induction, the simulation sometimes produced when one electrode of an induction apparatus is applied to a nerve. Synonym: unipolar induction action. Origin: Uni- + polar. Source: Websters Dictionary (01 Mar 1998) |
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| 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) |
| unipolar cell | A neuron whose cell body emits a single axonal process resulting from the fusion of two polar processes during development; at a variable distance from the cell body, the process divides into a peripheral axon branch extending outward as a peripheral afferent (sensory) nerve fibre, and a central axon branch that enters into synaptic contact with neuron's in the spinal cord or brainstem. With the single known exception of the neuron's composing the mesencephalic nucleus of the trigeminus, unipolar neuron's are the exclusive neural elements of the sensory ganglia. The lack of dendritic processes of these primary sensory neuron's is only apparent: the dendritic pole of the unipolar neuron is represented by the unmyelinated terminal ramifications of the peripheral axon branch. Synonym: pseudounipolar cell, pseudounipolar neuron, unipolar cell. (05 Mar 2000) |
| unipolar electrocardiogram | An electrocardiogram taken with the exploring electrode placed on the chest overlying the heart or upon a single limb, the indifferent ("zero" potential) electrode being the central terminal. (05 Mar 2000) |
| unipolar neuron | A neuron whose cell body emits a single axonal process resulting from the fusion of two polar processes during development; at a variable distance from the cell body, the process divides into a peripheral axon branch extending outward as a peripheral afferent (sensory) nerve fibre, and a central axon branch that enters into synaptic contact with neuron's in the spinal cord or brainstem. With the single known exception of the neuron's composing the mesencephalic nucleus of the trigeminus, unipolar neuron's are the exclusive neural elements of the sensory ganglia. The lack of dendritic processes of these primary sensory neuron's is only apparent: the dendritic pole of the unipolar neuron is represented by the unmyelinated terminal ramifications of the peripheral axon branch. Synonym: pseudounipolar cell, pseudounipolar neuron, unipolar cell. (05 Mar 2000) |
| augmented lead | Electrocardiogram recorded between one limb and two other limbs. The augmented lead are designated aVF, aVL, and aVR for recordings made between the foot (left), left arm, and right arm, respectively, and the other two limbs. (05 Mar 2000) |
| bipolar lead | A record obtained with two electrodes placed on different regions of the body, each electrode contributing significantly to the record; e.g., a standard limb lead. (05 Mar 2000) |
| black lead | Plumbago; graphite.It leaves a blackish mark somewhat like lead. See Graphite. Source: Websters Dictionary (01 Mar 1998) |
| red lead | A bright orange-red powder that turns black when heated; used in ointments and plasters. Synonym: red lead, red oxide of lead. (05 Mar 2000) |
| red oxide of lead | A bright orange-red powder that turns black when heated; used in ointments and plasters. Synonym: red lead, red oxide of lead. (05 Mar 2000) |
| CB lead | A bipolar chest lead with the negative electrode placed upon the subject's back. (05 Mar 2000) |
| V lead | A unipolar lead with the central terminal as the indifferent electrode; V is the symbol for unipolar (Latin "U"). (05 Mar 2000) |
| CF lead | A bipolar chest lead with the negative electrode placed on the subject's left leg. (05 Mar 2000) |
| CL lead | A bipolar chest lead with the negative electrode placed on the subject's left arm. (05 Mar 2000) |
| white lead | A heavy white powder that is insoluble in water; occasionally, it is used to relieve irritation in dermatitis, but it is used largely in the manufacture of paint and in the arts and is thus productive of lead poisoning. Synonym: ceruse, white lead. (05 Mar 2000) |