| delayed reaction experiment | A method of measuring memory: a stimulus is presented and removed before the organism is permitted to respond to it; the interval during which the stimulus is absent, providing the organism responds correctly, is an indication of the length of memory. (05 Mar 2000) |
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| delayed rectifier channel | <physiology> The potassium selective ion channels of axons, so called because they change the potassium conductance with a delay after a voltage step. The name is used to denote any axon like K channel. Various roles for example regulation of pacemaker potentials, generation of bursts of action potentials or generation of long plateaus on action potentials. (18 Nov 1997) |
| delayed reflex | A reflex in which a little time elapses between stimulus and response. See: trace conditioned reflex. (05 Mar 2000) |
| delayed sensation | A sensation that is not perceived until the lapse of an appreciable interval following the application of the stimulus. General sensation, a sensation referred to the body as a whole rather than to any particular part. (05 Mar 2000) |
| delayed suture | A suturing of a wound after an interval of days. (05 Mar 2000) |
| delayed type hypersensitivity | <immunology> Hypersensitivity (increased reaction by the body to a foreign substance such as an antigen or allergen) that does not appear until 24 to 48 hours after the body is exposed to the foreign substance. (09 Oct 1997) |
| ovum implantation, delayed | Delay of embryonal development whereby the blastocyst remains in the uterine cavity for a variable period of time before attaching to the endometrium and continuing its development. (12 Dec 1998) |
| abscess scan | <investigation> This is a nuclear scan that utilises radioactively tagged white blood cells. The patients white blood cells (taken from a small tube of blood) are tagged with radioactive indium. Later, the cells are then reinjected into the bloodstream. The coarse of the white blood cells can then be mapped using a gamma camera (radiation detecting device). The net result is a picture that shows the location of the radioactive white blood cells. The location of the white cells can indicated the presence of infection or inflammation. This test is useful in detecting a hidden source of bacterial infection, such as an abscess. (11 Mar 1998) |
| biliary scan | <investigation, radiology> A test that uses a radioactive tracer to look for bile duct obstruction or gallbladder inflammation. A special tracer is injected into a vein that tends to collect primarily in the liver. It is then excreted in the bile where it makes its way to the gallbladder. A gamma camera measures the tracer (radioactivity) and generates an image of the gallbladder and biliary system. (27 Sep 1997) |
| bone scan | <investigation, radiology> A study of the body skeleton. A dose of radioactive substance is injected and the scan (taken a little time later) reads the distribution of the radioactivity. (16 Dec 1997) |
| bone scan: falsely negative metastases | <radiology> Anaplastic tumours, reticulum cell sarcoma, renal cell carcinoma, thyroid carcinoma, histiocytosis, neuroblastoma, multiple myeloma (positive scan usually due to recent or impending fracture) (12 Dec 1998) |
| captopril renal scan | <radiology> In a kidney with a lesion in the afferent arteriole (e.g. Atherosclerotic plaque), reflex constriction of the efferent arteriole occurs through angiotensin system thus maintaining renal perfusion. ACE inhibition prevents constriction of efferent arteriole. Therefore, perfusion is decreased to a kidney with afferent lesions and the renal scan to looks WORSE. Bottom line: renal scans appear WORSE with captopril administration if there is a lesion in the afferent arteriole. See: renal artery stenosis (12 Dec 1998) |
| gallbladder scan | <investigation, radiology> A test that uses a radioactive tracer to look for bile duct obstruction or gallbladder inflammation. A special tracer is injected into a vein that tends to collect primarily in the liver. It is then excreted in the bile where it makes its way to the gallbladder. A gamma camera measures the tracer (radioactivity) and generates an image of the gallbladder and biliary system. (27 Sep 1997) |
| radionuclide scan | An exam that produces pictures (scans) of internal parts of the body. The patient is given an injection or swallows a small amount of radioactive material. A machine called a scanner then measures the radioactivity in certain organs. (12 Dec 1998) |
| ventilation-perfusion scan | A lung function test, especially useful for pulmonary embolism, employing an inhaled radionuclide for ventilation and an intravenous radionuclide for perfusion; their respective distributions in the lung are recorded scintigraphically. (05 Mar 2000) |