Biological Rhythyms: Circadian

Question 1

What are biological rhythms?

Answer 1

-Cyclical patterns.
-Evolve in response to biological influences.

Question 2

What are biological rhythms controlled by?

Answer 2

Endogenous peacemakers (internal) and exogenous zeitgebers (external)

Question 3

What is meant by circadian rhythms?

Answer 3

Rhythms which are subject to a 24 hour cycle.

Question 4

What do circadian rhythms regulate?

Answer 4

1. Sleep wake cycle.
2. Hormone production.
3. Body temperature.

Question 5

Outline Aschoff and Wever’s research on biological rhythms .

Answer 5

1. Made pps send 4 weeks in a WW2 bunker (no light)
2. Most pps developed a sleep wake cycle of between 24-25 hrs.
3. 1 pp developed a 29 hr cycle.

Question 6

Outline Folkard et al’s research on biological rhythms

Answer 6

12 pps in a cave for 3 weeks.
Only 1 pp could adjust to a 22 hr sleep wake cycle.

Question 7

Give 1 example of a circadian rhythm.

Answer 7

Body temp is highest at 7pm and lowest at 4am.

Question 8

What is meant by free running rhythm?

Answer 8

Rhythms longer than 24 hrs due to no exogenous zeitgebers.

Question 9

Give one weakness of circadian rhythms.

Answer 9

Research often involves small samples.
Siffre’s study contained 1 pp and Folkards contained 12.
Research is unlikely to be representative (generalisability).
More research with larger samples needed to be established as valid concept + generalise.

Question 10

Give 3 strengths of circadian rhythms.

Answer 10

1. Useful implications for medication.
   There are certain times where drugs are most effective.
   Improved guidelines for when to take medication for epilepsy, respiratory conditions etc.
   useful economic implications.
   Real life application.
2. Insight into consequences of desynchronisation (messing up circadian rhythm).
   A relationship between shift work and poor health was established.
   Shows disruption to circadian rhythms should be avoided.
   Research can inform work places how to manage work productivity.
3. Research support

1 man - 6 months.
Deprived of exposure to light in cave.
His free running rhythm settled to 25 hrs - continued to wake and slept at same time.