Circadian rhythm internal timing mechanism cycle of activity ~ 24 hours

circadian rhythm

• internal timing mechanism

• cycle of activity

• ~ 24 hours

suprachiasmatic nucleus

SCN of hypothalamus > pineal gland (melatonin)

suprachiasmatic nucleus

entrainment & SCN

What does it mean to “entrain” the SCN?

What cues can entrain the SCN?

jet lag

• fatigue & inefficiency

• body clock out of phase with timing of your surroundings

phase-advance

phase-delay

• body restoration

why sleep?

• strengthens learning & memory• evolutionary adaptation

evolutionary adaptation

• prevent injury in dark

• energy conservation

• predation & meal frequency

evolutionary adaptation

gorillas

bears

lions

grazing animals

EEG vs. EOG

electroencephalograph vs. electro-oculograph

awake

stage 1

stage 2

stage 3

stage 4

REM

relaxed wakefulness

slow wave sleep

slow wave sleep

• resembles wakefulness• irregular activity• paralysis (pons)

• rapid eye movement

overnight

slow wave sleep

REM

awake

stage 1

stage 2

stage 3

stage 4

REM• dreams w/ plot• paralysis

• sleepwalking• sleeptalking• night terrors

sleep disorders

insomnia

3 types:

- hard to fall asleep

- wake too early

- wake frequently overnight

insomnia

Restless Leg Syndrome

Do you ever clench or grind your teeth at night?

bruxism

discussion

As a child, ever wake up screaming?

Difference between

night terror & nightmare?

sleeping pills

benzodiazepines

“Ambien”

discussion

Should a person be accountable for their behavior?

“Ambien Drivers”

other

Heard stories of a guy attacking someone in his sleep?

REM Sleep Behavior Disorder

(violence?)

discussion

Difference between sleepwalking & REM Sleep Behavior Disorder?

discussion

When you awaken, you are paralyzed.

You can hear, feel, think but can’t move!

narcolepsy

a broad category

narcolepsy

sudden attacks of extreme, irresistible sleepiness midday

sleep paralysis

When you awaken, you are paralyzed.

You can hear, feel, think but can’t move!

hallucinations

• hypnopompic

• hypnogogic

cataplexy

loss of muscle control during high emotion

dreams

• environmental stimuli

ACTIVATION SYNTHESIS THEORY

• random pons firing activates brain

• cortical areas try to make sense of random info• frontal lobe is shut down so no logic

• issues preoccupied with