Biological Rhythms

Ultradian:

• Less than a day

• Slow wave sleep

• REM sleep

• SWS-REM-SWS

• The whole cycle takes 90 Min

• 4/6 Cycle’s a night

Infraidian:

• Less than one cycle in 24hrs

• Female menstrual

• Hibernation

Research:

• Russel,Switz and Thompson

• Pheromones rubbed on the participant’s lips

  • Menstrual cycle synchronised with donor

Circadian:

• Once a day

• Sleep-wake-synchronised with cycle

Regulated by:

• Endogenous pacemakers (internal)

  • SCN: Suprachiamatic nucleus

• Obtains light via optic nerve

• Sends signals to the pineal gland

• Melatonin increases at night and induces sleep

• Light in the morning decreases melatonin and we become alert

Exogenous Zietgebers:

• External

• Such as light

• Synchronise with internal body clock (Endogenous pacemaker)