Chapter 7 Definitions Flashcards
electromagnetic spectrum
a continuum ordered by teh wavelength or frequency of the energy produced
Hertz (Hz)
the number of cycles per second
megahertz (MHz)
one million cycles per second
alternating current
the uninterrupted flow of electrons marked by a change in the direction and magnitude of the movement
amplitude
the maximum departure of a wave from the baseline
transducer
a device that converts one form of energy to another
resonating
vibrating
collimated
possessing a beam of parallel rays or waves that form a column of energy
attenuation
the decrease in a wave’s intensity resulting from the absorption, reflection, and refraction of energy
unstable cavitation
the violent oscillation and subsequent rupture of bubbles during ultrasound application at too high an intensity
kilohertz (kHz)
one thousand cycles per second
pulse interval
the amount of time between ultrasonic pulses
pulse length
the amount of time from the initial nonzero charge to the return to a zero charge, forming one complete cycle
acoustical interface
a surface where two materials of different densities meet
standing wave
a single-frequency wave formed by the collision of two waves of equal frequency and speed traveling in opposite directions. The energy with a standing wave cannot be transmitted from one area to another and is focused in a confined area
eddy (eddies)
a circular current of fluid, often moving against the main flow
organelle
a specialized portion of a cell that performs a psecific function, such as the mitochondria and the Golgi apparatus
periosteal pain
a deep-seated resulting from overly intense application of ultrasonic energy that irritates the bone’s periosteum
cytokine
a protein produced by white blood cells
fibrinolysis
pathological breaking up of fibrin
free radical
a highly reactive molecule having an odd number of electrons. Free radical production plays an important role in the progression of an ischemic injury
chemosensitive pain receptors
nerves that are excited by the presence of certain chemcial substances
hydrocortisone
an anti-inflammatory drug that closely resembles cortisol
interferon gamma
a group of proteins release by white blood cells and fibroblasts when devouring the unwanted tissues. The gamma classification is also referred to as “angery macrophages” because of their heightened phagocytic activity
