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Biopsychology Year 2 > Biological Rhythms > Flashcards

Flashcards in Biological Rhythms Deck (14):

What is a biological rhythm?

A change in body processes in response to a cyclical change within the environment.


What are all rhythms controlled by?

Endogenous pacemakers (Internal biological clock)

Exogenous Zeitgebers (External changes in the environment).


What are endogenous pacemakers?

Your internal biological clock.


What are exogenous Zeitgebers?

External changes in the environment.


What are the three types of biological rhythms and how long are their cycles?

Circadian. = 24 hrs
Infradian. = More than 24 hours
Ultradian. = Less than 24 hours


What is a good word to use for saying the resetting a rhythm?



What is the role of the SCN?

Regulate when you are asleep and when you are awake.


What are the three steps that the SCN are involved in?

1 - As light enters the eye, it travels to the SCN.
The light = EZ
The SCN = EP.

2 - The SCN then regulates the activity of the pineal gland.

3 - In response, the pineal gland either secretes or decrease the production of the hormone melatonin depending on whether it is high or low light.


If there is low light, will there be more or less melatonin produced?

More melatonin.


Is there is lots of light, will there be more or less melatonin?

Less melatonin.


What is a case study that can be used?

Sifre - Cave Study,


What happened in the Sifre Cave Study?

- 6 months in a cave with no natural light (EZ)

- Wanted to see if he could 'free-run' his circadian rhythm.

- Found his body adjusted to approx 25-27 hours.


What did the Sifre Cave Study show us?

We do have a natural rhythm and light entrains our circadian rhythm.


What is the problem with using the Sifre Cave Study to demonstrate?

It is a case study so it is hard to generalise the findings.