Biological rhythms Flashcards
What is an exogenous zeitgeber
An external influence that helps to entrain our biological rhythms
What is an endogenous pacemaker
An internal influence that helps to entrain our biological rhythms
Name an example of an exogenous zeitgeber
Light or social cues
Name an example of an endogenous pacemaker
The suprachiasmatic nucleus
How do exogenous zeitgebers and endogenous pacemakers work together to
- Exogenous zeitgeber taken in
- Information passes the optic chiasm
- Information sent to the suprachiasmatic nucleus
- Information sent to the pineal gland
- Low light causes melatonin to be produced, which causes people to sleep.
What is the frequency of a circadian rhythm
One cycle in 24 hours
What is the frequency of a infradian rhythm
Less than one cycle in 24 hours
What is the frequency of a ultradian rhythm
More than one cycle in 24 hours
Name an example of a circadian rhythm
Sleepwake cycle
Core body temperature
Name an example of an infradian rhythm
Menstrual cycle
Seasonal affective disorder
Name an example of an Ultradian rhythm
Stages of sleep
What did DeCoursey (2000) do
He removed the connections of the suprachiasmatic nucleus in the brains of chipmunks
What did Siffre do
He went without exogenous zeitgebers for 2 months to research the effects on his sleep wake cycle (he thought it was only one month)
What kind of people have no darkness for prolonged period of time
People who live in arctic regions, they still retain a 24 hours sleepwake cycle
What influence does current research into circadian rhythms ignore
The influence of social norms
