Biological Rhythms: Circadian. Flashcards
A2 content
What is a biological rhythm?
Distinct patterns of changes in the body activity that conform to cyclical time periods.
What is a circadian rhythm?
A biological rhythm that is subject to a 24 hour cycle which regulate a number of bodily processes.
Can you give an example of two circadian rhythms?
Core body temperature and the sleep wake cycle.
What might affect a biological rhythm such as a circadian rhythm?
Internal bodily clocks (endogenous pacemakers) and external changes in environment (exogenous zeitgerbers)
What are some examples of research into circadian rhythms?
Folkard, Siffree
What did Siffree find when spending time in a cave?
His biological clock settled down to 25 hours- just outside the normal 24 hours.
What did Folkard find in his research?
After trying to speed up a clock in a cave to represent a 22 hour cycle, the 11/12 of the participants struggled to adjust. Suggesting naturally people have a 24 hour sleep cycle.
Name some exogenous zeitgerbers that might influence our sleep wake cycle
Light, social cues, eating etc
How does the endogenous pacemaker work?
The body picks up on light through the optic chiasm, the suprachiasmatic nucleus refers the information of dark and light to the pineal gland which subsequently releases melatonin in the body at these times for sleep and wakefulness.
What is a strength of circadian rhythms?
Been used to improve medical treatments e.g chronotheraputics.
E.G taking aspirin late at night for blood pressure as that is when it is at its lowest.
What is a limitation of circadian rhythms?
Most research is based on small samples and therefore might not be generalisable.
Why is there an argument that changing the school day wouldn’t benefit students?
They may stay up even later which would mean the same situation of sleep debt etc.
