Biological rhythms Flashcards
What are circadian rhythms?
Biological rhythms that last aprox. 24 hours
Who spent six months in a cave and what did he find?
Siffre found that light was essential for the 24 hour sleep/wake cycle
What are endogenous pacemakers?
Rhythms from internal body systems that regulate biological rhythms
What are exogenous zeitgebers?
External cues from the environment that affect biological rhythms
What is the most influential endogenous pacemaker?
Suprachiasmatic nucleus
Where is the SCN and what does it do?
The middle of the brain, connected to the hypothalamus; controls biological rhythms
What suggests that the SCN has an evolutionary feature?
It is found in animals as well as humans
What is entrainment?
An adjustion of the body clock to fit with the environment
Who gave light-therapy to mothers of premature babies and found it improved their sleep quality?
Shih-Yu Li
What are infradian rhythms?
Biological rhythms that last longer than 24 hours
Who found that pheremones from a woman at the beginning or end of her menstrual cycle could lengthen or shorten another woman’s cycle?
McClintlock
What are ultradian rhythms?
Biological rhythms lasting less than 24 hours
Give an example of a circadian rhythm
The sleep/wake cycle
Give an example of an ultradian rhythm
A sleep cycle
Give an example of an infradian rhythm
The menstrual cycle
