- Created by: Elizabeth Wright
- Created on: 03-01-13 14:26
Discuss Endogenous pacemakers and exogenous zeitgebers
An endogenous pacemaker is something that happens inside of our bodies such as biological rhythms. The suprachiasmatic nucleus (SCN) is something that is in out brain that lies in our hypothalamus. Its job is to obtain information about light through the optic nerve in the eye. The purpose of this is to reset our biological clock so our rhythm becomes in sync with the time of the day. This is supported by the study conducted with hamsters by Morgan (1995). Some hamsters were bred to have mutant SCN’s. The mutant SCN was then placed into a hamster with a normal SCN. The results were that the ‘normal’ hamster then took on the SCN of the mutant hamsters. This provides evidence for the idea that our rhythms are biological and that we are born with them. The pineal gland produced melatonin which can induce sleep. Melatonin production can be guided by light and dark. When it is dark, melatonin is produces. This supports the idea that there are two systems; endogenous pacemakers and exogenous zeitgebers and that they work together rather than the idea of there being on separate system.
Exogenous zeitgebers are external cues that…