effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle

what are endogenous pacemakers

internal body clocks that regulate biological rhythms

what are exogenous pacemakers

external factors which entrain our endogenous pacemakers

what are the four main areas of the brain involved in the sleep wake cycle

suprachiasmatic nucleus, optic chiasm, hypothalamus, pineal gland

what is the exogenous pacemaker in the sleep wake cycle

light levels

what is the endogenous pacemaker in the sleep wake cycle

suprachiasmatic nucleus

what is the role of the eyes in the sleep wake cycle

our eyes detect when the light levels decrease at night

what role does the optic chiasm have in the sleep wake cycle

the optic nerve sends the info from the eyes up through the optic chiasm to the suprachiasmatic nucleus located in the hypothalamus

what role does the suprachiasmatic nucleus have in the sleep wake cycle

the suprachiasmatic nucleus tells the pineal gland to produce more melatonin

what role does the pineal gland have in the sleep wake cycle

the pineal gland produces more melatonin which makes a person fall asleep

individual differences - evaluation

Czeisler found individual differences in the sleep wake cycles varying from 13 hours to 65 hours

studying in isolation - evaluation

in Siffre’s study he was in a cave to isolate his endogenous pacemaker by eliminating light

environmental impacts - evaluation

people who live in places such as the arctic circle which get 6 months of darkness have similar sleep cycles to everyone else