- Internal pacemakers
- Circidian- 24hrs
- Infradian- More than 24hrs
- Ultradian- Less than 24hrs
- Located on top of head
- Detects light and produces melatonin if there is anticpated darkness.
- Abraham- Injected sparrow with melatonin and they fell asleep.
SCN- Suprachiasmatic nucleus
- Located above the optic chiasm
- Responible for controlling the circidian cycles.
- Morgan, removed…