Physicians Desk Reference Physicians Desk Reference
Browsable database of medical products, manufacturer, therapeutic categories, indication, contra indication, side effects, drug and food interaction.
Medical Product | Medical Manufacturer | Therapheutic | Indication | Contra Indication | Side Effect | Drug Interaction | Food Interaction


resonance (rez´o-nans)

1. Sympathetic or forced vibration of air in the cavities above, below, in front of, or behind a source of sound; in speech, modification of the quality (e.g., tone) of a sound by the passage of air through the chambers of the nose, pharynx, and head, without increasing the intensity of the sound. 2. The sound obtained on percussing a part that can vibrate freely. 3. The intensification and hollow character of the voice sound obtained on auscultating over a cavity. 4. In chemistry, the manner in which electrons or electric charges are distributed among the atoms in compounds that are planar and symmetrical, particularly those with conjugated (alternating) double bonds; the existence of r. in the latter case lowers the energy content and increases the stability of a compound. 5. The natural or inherent frequency of any oscillating system. 6. resonant frequency [L. resonantia, echo, fr. re-sono, to resound, to echo]
amphoric r. a percussion sound, like that produced by striking a large empty bottle, obtained by percussing over a pulmonary cavity.cavernous r;
bandbox r. vesiculotympanitic r
bellmetal r. in cases of a large pulmonary cavity or of pneumothorax, a clear metallic sound obtained by striking a coin, held against the chest, by another coin, or by flicking the chest wall with one's fingernail; the sound is heard on auscultating the chest wall on the same side anteroposteriorly.anvil sound, bell sound, coin test;
cavernous r. amphoric r
cracked-pot r. a peculiar sound, resembling that heard on striking a cracked pot, elicited on percussing over a pulmonary cavity that commmunicates with a bronchial tube, when the patient's mouth is open.cracked-pot sound;
electron paramagnetic r. (EPR) electron spin r
electron spin r. (ESR) a spectrometric method, based on measurement of electron spins and magnetic moments, for detecting and estimating free radicals in reactions and in biological systems.electron paramagnetic r;
hydatid r. a peculiar vibratile r. heard on auscultatory percussion over a hydatid cyst.
nuclear magnetic r. (NMR) the phenomenon in which certain atomic nuclei possessing a magnetic moment will precess around the axis of a strong external magnetic field, the frequency of precession (Larmor frequency) being specific for each nucleus and the strength of the magnetic field; spinning nuclei induce their own oscillating magnetic fields and therefore emit electromagnetic radiation that can produce a detectable signal at the Larmor frequency. NMR is used as a method of identifying covalent bonds and is applied clinically in magnetic resonance imaging.
skodaic r. a peculiar, high-pitched sound, less musical than that obtained over a cavity, elicited by percussion just above the level of a pleuritic effusion.Skoda's sign, Skoda's tympany;
tympanitic r. tympany
vesicular r. the sound obtained on percussing over the normal lungs.
vesiculotympanitic r. a peculiar, partly tympanitic, partly vesicular sound, obtained on percussion in cases of pulmonary emphysema.bandbox r., wooden r;
vocal r. (VR) the voice sounds as heard on auscultation of the chest.
wooden r. vesiculotympanitic r


Browse Medical References:

[A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M]
[N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Y] [Z]