A2 - Biological Rhythms and Sleep

Question 1

Sleep -wake cycle - why do we sleep and wake at regular times?

Answer 1

Daylight

Question 2

How is the sleep-wake cycle investigated?

Answer 2

Temporary isolation studies - biological clock runs without external cues

Question 3

Give an example of a temporary isolation study.

Answer 3

Michael Siffre spent time living underground to reset his biological clock with no external cues just his free running rhythm. He found the sleep wake cycle is 24hrs but could be 48hrs as internal clock slows with age.

Question 4

The amount people sleep per night varies, why is this?

Answer 4

Individual differences

Question 5

Core body temp. - when is the body’s temperature at its lowest?

Answer 5

4:30am 36C

Question 6

When is body temperature at its highest?

Answer 6

6:00pm 38C

Question 7

When is there a slight dip in body temperature?

Answer 7

After lunch

Question 8

Hormone production - when is cortisol at its lowest and highest?

Answer 8

Lowest= 12am Highest = 6am

Question 9

Why do we feel tired and less alert when we wake up too early?

Answer 9

There is a lack of cortisol the hormone produced during stress that makes us alert when we wake up.

Question 10

What is the definition of a circadian rhythm?

Answer 10

A bodily rhythm that lasts about 24hrs