Chapter 14: Biological Rhythms, Sleep, and Dreaming

• Circadian rhythms

• Diurnal

• Nocturnal

• Zeitgeber

• free-running rhythm

• phase shift

• period

• functions of an organism that display a rhythm of about 24 hours

• active during the day

• active during the night

• (time giver) a rhythmically occurring natural phenomenon which acts as a cue in the regulation of the body's circadian rhythms

• A biological rhythm that is not synchronized to external cues

• The shift in activity in response to a synchronizing stimulus

• the time between two similar points in successive cycles

• Why have a circadian rhythm?

• Suprachiasmatic nucleus (SCN)

• What gland is sensitive to light in amphibians and birds?

• retinohypothalamic pathway

• tau mutations and double clock mutants

• synchronizes an animal’s behavior and body states to daily rhythms in the environment.

  • The endogenous clock enables animals to anticipate an event in their environment

• the biological clock in the hypothalamus

• the pineal gland

• how light information goes from the eye to the SCN in mammals

• gene mutations that make periods shorter and severely arrhythmic

• infradian rhythms

• ultradian rhythms

• rhythms longer than a day (the menstrual cycle)

• occur more than once per day (minutes to hours)

• What is sleep synchronized to?

• Electrical brain potentials can be used to do what?

• Electroencephalography (EEG)

• Electro-oculography (EOG)

• Electromyography (EMG)

• What are the two classes of sleep?

• external events, including light and dark

• classify levels of arousal and states of sleep

• records electrical activity in the brain

• records eye movements

• records muscle activity

• Non-REM sleep and REM sleep

• Non-rem sleep

• Rapid eye movement sleep (REM)

• What are the characteristics of sleep

• How long do cycles last for?

• divided into 3 stages and is characterized by lack of rapid eye movements

• is characterized by small amplitude fast egg waves, no postural tension, and rapid eye movements

• sleep times ranger from 7-8 hours with 50% being stage two and 20% being REM sleep

• 90-110 minutes

• What does puberty do to the circadian rhythm

• Nightmares

• Night terrors

• What are the biological functions of sleep?

• What are the four systems that mediate sleep

• the cycle gets pushed back to later in the day

• are frightening dreams that waken the sleeper from REM sleep

• sudden arousals from NREM sleep, marked by fear and autonomic activity

• to conserve energy, enforce niche adaptation, restore the body and brain, and aid memory consolidation

• a forebrain system that generates SWS, a brainstem system that activates the forebrain into wakefulness, a pons system that triggers REM sleep, and a hypothalamic system that affects the other three

• what are the effects of sleep deprivation

• increased irritability

• difficulty in concentrating

• episodes of disorientation