session 10 Flashcards
Circadian Rhythms
24-hour schedules with rotating hormone levels, body-temperatures, and levels of wakefulness
Zeitgeber
“time-giver”, what sets our rhythms, sunlight is a natural one, exercise, time of day, body temp, artificial light also play a role
suprachiasmatic nucleus
just behind the eyes and below he optic chiasm
retinal input
like a blind mole rat has no conscious reaction to light, but still has a suprachiasmatic nucleus
retinohypothalamic pathway
starts in the periphery of the retina, provides the SCN with input
Period and Timeless genes
produce PER and TIM proteins throughout the day, promote drowsiness as they build up, but then production is halted allowing them to wear off and allow wakefulness the next morning
Melatonin
promotes drowsiness
Histamine and Orexin
promote wakefulness
Polysomnograph
sleep cycles measured with a polysomnography
-measure brain waves
-measures eye movements
-advanced procedures also measure blood oxygenation and air flow/labor to breathe
sleep cycles
primarily defined by brain wave fluctuations
Paradoxical Sleep (REM sleep)
brain waves similar to waking state, and rapid eye movements
PGO waves
(ponse, geniculate, occipital cortex) are a signature of REM sleep
-brain stem-initiated visual perceptions (dreaming)
REM Rebound
shows us that the brain values REM sleep above other stages, it decreases as we age
Brain phases
in and out of sleep at the same time, but sometimes parts are more awake than others
-GABA levels
- shuts down sensory perceptions
Nightmares
“bad dreams”
