Lesson 11 - Circadian Rhytms

Question 1

What are Biological rhythms ?

Answer 1

Biological Rhythms are cyclical changes in physiological systems.

Question 2

What is a circadian rhythm ?

Answer 2

Its a cycle that lasts 24 hours.

Question 3

What controls circadian rhythms ?

Answer 3

They are driven by the suprachiasmatic nuclei in the hypothalamus. Natural light provides the input to this system, setting the SCN to the right time. The scn uses this to coordinate activity of circadian rhythms throughout the body.

Question 4

What is a strength of Circadian Rhythms ?

Answer 4

Its been applied with chronotherapeutics. Medicines have been developed to be taken before sleep but to be realised at the most vulnerable times

Question 5

What is a weakness of Circadian Rhythms ?

Answer 5

Czeisler found that cycles can vary from 13 to 165 hours. Individual differences.

Question 6

What is a weakness of Circadian Rhythms ?

Answer 6

Morning people and evening people

Question 7

Outline Siffres study

Answer 7

Spent 179 days in a cave with no natural light. Siffre body clock maintained a sleep - wake cycle of 25 hours - longer than expected 24 hours.

Question 8

What is a weakness of Siffre study?

Answer 8

Can’t be generalised to wider pop, suffer only one guy.