| junction | 1. The act of joining, or the state of being joined; union; combination; coalition; as, the junction of two armies or detachments; the junction of paths. 2. The place or point of union, meeting, or junction; specifically, the place where two or more lines of railway meet or cross. Junction plate, the switch, or movable, rails, connecting one line of track with another. Origin: L. Junctio, fr. Jungere, junctum, to join: cf. F. Jonction. See Join. Source: Websters Dictionary (01 Mar 1998) |
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| junction nevus | A nevus consisting of nests of melanocytes in the basal cell zone, at the junction of the epidermis and dermis, appearing as a slightly raised, small, flat, nonhairy pigmented (brown or black) tumour. Synonym: epidermic-dermic nevus. (05 Mar 2000) |
| junction of lips | The junction of the lips lateral to the angle of the mouth. Synonym: commissura labiorum, junction of lips. (05 Mar 2000) |
| ureteropelvic junction | Site of origin of the ureter from the renal pelvis, a common location for congenital or acquired obstruction. (05 Mar 2000) |
| ureteropelvic junction obstruction | <urology> A blockage of a ureter in the region where the ureter enters the anatomic pelvis (close to the bladder). This is caused most often by a kidney stone but can also be caused by external (or internal) compression from a tumour. (27 Sep 1997) |
| action potential | <physiology> The sequential, electrochemical polarization and depolarisation that travels across the membrane of a nerve cell (neuron) in response to stimulation (touch, pain, cold, etc.) (09 Oct 1997) |
| bioelectric potential | Electrical potential's occurring in living organisms. (05 Mar 2000) |
| biological hazard potential | <radiobiology> Measure of the hazard posed by a given quantity of radioactive material in which the variation in biological effects of the various elements are accounted for. See: integrated biological hazard potential. (21 Mar 1998) |
| biotic potential | <biology, ecology> The potential growth a population of living things can expect if it were living under ideal environmental circumstances. (19 Jan 1998) |
| body surface potential mapping | Recording of regional electrophysiological information by analysis of surface potentials to give a complete picture of the effects of the currents from the heart on the body surface. It has been applied to the diagnosis of old inferior myocardial infarction, localization of the bypass pathway in wolff-parkinson-white syndrome, recognition of ventricular hypertrophy, estimation of the size of a myocardial infarct, and the effects of different interventions designed to reduce infarct size. The limiting factor at present is the complexity of the recording and analysis, which requires 100 or more electrodes, sophisticated instrumentation, and dedicated personnel. (12 Dec 1998) |
| brain potential | <physiology> The electrical charge of the brain as compared to a point on the body; the potential may be steady (DC potential) or may fluctuate at specific frequencies when recorded against time, giving rise to the electroencephalogram. (05 Mar 2000) |
| pacemaker potential | The voltage inscribed by impulses from an artificial electronic pacemaker. (05 Mar 2000) |
| generator potential | Local depolarisation of the membrane potential at the end of a sensory neurone in graded response to the strength of a stimulus applied to the associated receptor organ, e.g., a pacinian corpuscle; if the generator potential becomes large enough (because the stimulus is at least of threshold strength), it causes excitation at the nearest node of Ranvier and a propagated action potential. (05 Mar 2000) |
| receptor potential | The transmembrane potential difference of a sensory cell. Such cells are not generally excitable, but their response to stimulation is a gradual change in their resting potential. (18 Nov 1997) |
| redox potential | <chemistry> The reducing/oxidizing power of a system measured by the potential at a hydrogen electrode. (18 Nov 1997) |