PSYC 210 - Biological Rhythms Flashcards
The __________ rhythm is a yearly, migratory cycle.
circannual
The _________ rhythm is longer than a day, monthly, such as the menstrual cycle.
infradian
The __________ rhythm is a cycle that happens every 24 hours, daily, such as the human-sleep-wake cycle.
circadian
_________ rhythm is a cycle that happens within a few hours, or a day, such as meals or sleep cycles.
ultradian
Humans and animals have ________ for biological rhythms.
endogenous clocks
Cues that synchronize biological rhythms
zietgeber
the process of synchronizing an endogenous biological rhythm to the rhythm of an environmental cue
entrainment
Humans and animals show __________ despite living in a constant light or constant dark environment.
biological rhythms
spontaneous rhythm in environments without changes in lightness
free running rhythm
Human free running circadian rhythm is on average ______ than 24 hours.
greater
With exposure to sunlight during the day and darkness at nighttime, animals and humans express an _________ circadian rhythm.
entrained
During constant light or constant dark, animals express a _________ circadian rhythm.
free running
The ______ of the hypothalamus is the master oscillator of biological rhythms.
SCN
Individual ______ neurons fire rhythmically in a tissue culture.
SCN
Rhythmic SCN neuronal activity is __________.
genetically programmed
________ genes are also found in cells of other organs.
clock
_______ coordinates cells that control the rhythmic occurrence of different physiological events or behaviors (e.g., digestion, blood pressure, sleep).
SCN
Lesions of the SCN lead to irregular locomotor activity patterns (_______).Transplant of __________ SCN cells restores the circadian rhythm of locomotor activity.
arrhythmic, embryonic
The SCN gets light cue from the ____________ tract. Light signal is transmitted from a small population of retinal ganglion cells (neurons) to the SCN of the ___________.
retinohypothalamic, hypothalamus
Intrinsically photosensitive retinal ganglion cells have no image-forming function, but detect _____________ and express ___________, a light-sensitive substance.
brightness, melanopsin
Loss of ipRGCs causes an exhibition of ___________ rhythm because no way to interpret light information.
free running
___% of neurons are retinal ganglion cells.
95
__% of neurons are ipGRCs that don’t need input, just light.
5
_________ can be caused by travel, work shifts, or social.
jet lag
Jet lag can be reduced by ____ exposure & intensity, meal _________, and weekend sleep catch up.
light, entrainment
_________ rhythm is formed based on changes in the length of the light cycle throughout the year.
circannual
You secrete melatonin longer in the _________.
winter
The ______ gland secretes melatonin at nighttime.
pineal
When it becomes dark outside, the pineal gland secretes ______ melatonin.
more
_____ is involved in circannual rhythm. Male testosterone secretion is inhibited by the large amount of __________ in the winter.
SCN, melatonin
Hamsters engage in more sexual behavior in the summer when melatonin production ____________ because gonads will grow and ___________ hormone production that stimulates sexual behavior.
decrease, increase
Symptoms of winter SAD can be alleviated using ___________ (30 minutes) in the morning.
light exposure
Dark environment in the winter can increase depressive symptoms.
Winter SAD
If the SCN is intact, people can express __________ and _________ rhythm.
free running, entrained circadian
If a person has an intact SCN, but both eyes have lost melanopsin and ipRGC, they cannot show entrained circadian rhythm, but instead ___________ rhythm.
free running
If there are lesions in the SCN only __________ rhythm will be expressed.
irregular
