Biopsychology: Endogenous Pacemakers and Exogenous Zeitgebers

Question 1

Define Endogenous Pacemaker

Answer 1

Internal Body clock that regulate many of our biological rhythms, such as the influence of the superchiasmatic nucleus on the sleep/wake cycle

Question 2

Define Exogenous Zeitgebers

Answer 2

External cues which may affect or entrain our biological rhythms, such as the influence of light on our sleep/wake cycle

Question 3

Describe endogenous pacemakers and the sleep/wake cycle

Answer 3

Superchiasmatic nucleus located in the brain is the primary endogenous pacemaker
Receives information from light via the optic nerve
Sends message to pineal glad
Which releases melatonin at night

Question 4

Outline research into endogenous pacemakers and the sleep/wake cycle

Answer 4

Ralph
bred mutant hamsters with 20-hour sleep/wake cycle
transplanted their SCN cells into normal hamsters
hamsters adapted to 20 hour sleep/wake cycle showing importance of SCN (endogenous pacemakers)

Question 5

Outline exogenous Zeitgebers and the sleep/wake cycle

Answer 5

Light:
- Murphy light on back of knees shows exogenous zeitgebers are powerful
Social Cues:
- eating time
- social events
- work