Search results
Results from the WOW.Com Content Network
If the pressure is dropped to a level equal to that of the patient's systolic blood pressure, the first Korotkoff sound will be heard. As the pressure in the cuff is the same as the pressure produced by the heart, some blood will be able to pass through the upper arm when the pressure in the artery rises during systole. This blood flows in ...
This effect is responsible for guided propagation of sound waves over long distances in the ocean and in the atmosphere. In the atmosphere, vertical gradients of wind speed and temperature lead to refraction. [1] The wind speed is usually increasing with height, which leads to a downward bending of the sound rays towards the ground.
Sound pressure is the difference, in a given medium, between average local pressure and the pressure in the sound wave. A square of this difference (i.e., a square of the deviation from the equilibrium pressure) is usually averaged over time and/or space, and a square root of this average provides a root mean square (RMS) value.
Auscultation (based on the Latin verb auscultare "to listen") is listening to the internal sounds of the body, usually using a stethoscope. Auscultation is performed for the purposes of examining the circulatory and respiratory systems (heart and breath sounds), as well as the alimentary canal. The term was introduced by René Laennec. The act ...
Ultrasound energy, simply known as ultrasound, is a type of mechanical energy called sound characterized by vibrating or moving particles within a medium. Ultrasound is distinguished by vibrations with a frequency greater than 20,000 Hz, compared to audible sounds that humans typically hear with frequencies between 20 and 20,000 Hz.
There is also another effect called sound refraction, when there is a layer of cold air above or below a layer of hot air, (which typically happens at night as the earth cools and the warm air rises, but also happens on hot days when the earth heats up but the air above is still cool) sounds do actually travel further and therefore would seem ...
Arterioles carrying blood to superficial capillaries under the surface of the skin can shrink (constrict), thereby rerouting blood away from the skin and towards the warmer core of the body. This prevents blood from losing heat to the surroundings and also prevents the core temperature dropping further. This process is called vasoconstriction.
Although the ear is the primary organ for sensing low sound, at higher intensities it is possible to feel infrasound vibrations in various parts of the body. The study of such sound waves is sometimes referred to as infrasonics , covering sounds beneath 20 Hz down to 0.1 Hz (and rarely to 0.001 Hz).