| Jewett sound | A short straight sound for dilating the anterior urethra. (05 Mar 2000) |
|---|---|
| first heart sound | Occurs with ventricular systole and is mainly produced by closure of the atrioventricular valves. (05 Mar 2000) |
| fourth heart sound | The sound produced in late diastole in association with ventricular filling due to atrial systole and related to reduced ventricular compliance. It is a low frequency oscillation that may be normal at older ages owing to a physiologic decline in ventricular compliance but is nearly always abnormal at younger ages if it is of high intensity or palpable. It is common in ventricular hypertrophy, particularly with hypertension, and is almost invariable during acute myocardial infarction. Fourth heart sounds may arise from the right or left ventricle or both. Synonym: atrial sound. (05 Mar 2000) |
| friction sound | The sound, heard on auscultation, made by the rubbing of two opposed serous surfaces roughened by an inflammatory exudate, or, if chronic, by nonadhesive fibrosis. Synonym: friction murmur, friction rub. (05 Mar 2000) |
| Le Fort sound | A curved sound threaded for a filiform bougie, used for dilation of urethral strictures in the male when small caliber or presence of false passages prevents safe passage of a standard sound or catheter. (05 Mar 2000) |
| acid wave | A temporary increase in the acidity of the urine occurring during fasting. Synonym: acid wave. (05 Mar 2000) |
| alkaline wave | A period of urinary neutrality or even alkalinity after meals due to withdrawal of hydrogen ion for the purpose of secretion of the highly acid gastric juice. Synonym: alkaline wave. (05 Mar 2000) |
| alpha wave | Brain waves in the encephalogram which have a frequency of 8 to 13 per second. They are typical of the normal person awake and in a quiet resting state, and occur principally in the occipital region. (12 Dec 1998) |
| arterial wave | A wave in the jugular phlebogram due to transmission of carotid artery pulsation. B wave, the initial positive deflection in the electroretinogram, possibly arising from the inner nuclear layer of the retina. (05 Mar 2000) |
| A wave | The initial negative deflection in the electroretinogram, presumably reflecting retinal photoreceptor activity, an atrial deflection in an electrocardiogram recorded from within the atrium of the heart, the first positive deflection of the atrial and venous pulses due to atrial systole. (05 Mar 2000) |
| beta wave | <neurology> Brain waves in the electroencephalogram which have a frequency of 18 to 30 per second. They are typical during periods of intense activity of the nervous system, and occur principally in the parietal and frontal regions. (12 Dec 1998) |
| brain wave | Colloquialism for electroencephalogram. (05 Mar 2000) |
| brain wave complex | A specific combination of fast and slow electroencephalographic activity that recurs frequently enough to be identified as a discrete phenomenon. (05 Mar 2000) |
| brain wave cycle | The complete upward and downward excursion of a single wave, complex, or impulse as seen on an electroencephalogram. (05 Mar 2000) |
| brain wave test | <investigation> A diagnostic test which measures the electrical activity of the brain (brain waves) using high sensitive recording equipment attached to the scalp by fine electrodes. Commonly employed in the evaluation of neurological disease (for example seizures, epilepsy, etc.). Acronym: EEG (13 Nov 1997) |