Chapter 10: Biological rhythms and sleep Flashcards
A pattern of behavioral, biochemical, or physiological fluctuation that has a 24-hour period.
circadian rhythm
The slowest type of EEG wave, characteristic of stage 3 sleep.
delta wave
The recording and study of gross electrical activity of the brain via large electrodes placed on the scalp.
electroencephalography (EEG)
The process of synchronizing a biological rhythm to an environmental stimulus.
entrainment
Referring to a rhythm of behavior shown by an animal deprived of external cues about time of day.
free-running
An amine hormone that is secreted by the pineal gland at night, thereby signaling day length to the brain.
melatonin
A sudden arousal from stage 3 sleep that is marked by intense fear and autonomic activation.
night terror
A shift in the activity of a biological rhythm, typically provided by a synchronizing environmental stimulus.
phase shift
Also called paradoxical sleep. A stage of sleep characterized by small-amplitude, fast-EEG waves, no postural tension, and rapid eye movements
rapid-eye-movement (REM) sleep
Also known as non-REM sleep. Sleep, divided into stages 1–3, that is defined by the presence of slow-wave EEG activity.
slow-wave sleep (SWS)
A small region of the hypothalamus above the optic chiasm that is the location of a circadian clock.
suprachiasmatic nucleus (SCN)
Literally, “time-giver” (in German). The stimulus (usually the light-dark cycle) that entrains circadian rhythms.
zeitgeber
Referring to a rhythmic biological event whose period is longer than that of a circadian rhythm—that is, longer than a day
infradian
Referring to a rhythmic biological event whose period is shorter than that of a circadian rhythm, usually from several minutes to several hours long.
ultradian
