BIOPSY CHAP 8

Among adult humans, those who sleep ____ or more hours per night have the highest percentage of REM sleep.

9

Margie just had a polysomnograph taken. What did they measure?

A combination of her EEG and eye-movement records.

REM sleep is characterized by which of the following?

A high level of brain activity

What happens after damage to the suprachiasmatic nucleus itself?

Animals' activity patterns become less consistent and no longer respond to light and dark cycles.

Bright light late in the afternoon shortens the circadian rhythm.

False

During sleep, what happens in the brain?

Increased firing by GABA neurons

What is the role of the suprachiasmatic nucleus in circadian rhythms?

Its neurons generate a 24-hour rhythm by themselves.

Which hypothesis suggests that dreams are just thinking that takes place under unusual conditions?

Neurocognitive

Sometimes people find themselves unable to move their postural muscles immediately after awakening. Why?

Part of the brain is still asleep

Which of these is characteristic of sleep apnea?

Periods without breathing during sleeping

During ____, cells in the pons send messages that inhibit the motor neurons that control the body's large muscles.

REM sleep

Lena is taking antidepressants that increase her levels of serotonin. What is likely true about her sleep?

She experiences less REM sleep.

Cari's EEG recording shows sleep spindles and K-complexes. What is happening?

She has entered Stage 2 sleep.

Carlee's EEG recording shows a predominant amount of alpha waves. What is going on?

She is very relaxed but still awake

What is the best way to determine if an individual who claims to never dream does, in fact, have dreams?

Wake them up during REM sleep and ask them if they have been dreaming.

Stimulation of the pontomesencephalon ____.

awakens a sleeping individual

If suprachiasmatic nucleus neurons are disconnected from the rest of the brain, they ____.

continue to produce activity that follows a circadian rhythm

Researchers have demonstrated that the expression of the SCN genes can be changed through ____

exposure of the eyes to light

Olinda is blind; therefore, she does not have circadian rhythms.

false

The input from the eyes to the suprachiasmatic nucleus, responsible for shifting the phase of the circadian rhythm, originates from ____.

ganglion cells that are not connected to any cones or rods

Larisa has REM behavior disorder. What happens to her during REM sleep?

he moves around as if she is acting out her dreams.

Professor Cheng tells her class that the SCN is found in the _____

hypothalamus

Compared to REM, research suggests that NREM is ____

important for strengthening memories of lists of words

A disruption of circadian rhythms due to crossing time zones is known as ____.

jetlag

Based on research, it has been determined that the human circadian rhythm appears to be ____.

just over 24

The pineal gland releases the ____ hormone, which influences both circadian and circannual rhythms.

melatonin

Deonna is in a research study where she was asked to become sleep-deprived. She is mostly likely doing to see disruptions while doing ______tasks.

memory

While Arlette is sleeping, her locus coeruleus is ____

mostly inactive

Loss of orexin-containing neurons in the hypothalamus may contribute to ____.

narcolepsy

EEG waves are larger when brain activity decreases because ____.

neurons are becoming more synchronized

Night terrors can be distinguished from nightmares in that night terrors ____

occur during NREM sleep

The ____ is a structure that extends from the medulla into the forebrain.

reticular formation

A small branch of the optic nerve, known as the ____ path extends directly from the retina to the SCN.

retinohypothalamic

After damage to the suprachiasmatic nucleus, the body ____.

still has rhythms, but they are less consistent

After removing all sensory input to the brain, an animal would continue to have periods of sleep and wakefulness.

true

The activation-synthesis theory of dreams argues that dreams are the result of random brain activity.

true

Someone in a(n) ____ state alternates between periods of sleep and moderate arousal, although even during the more aroused state, the person shows no awareness of surroundings and no purposeful behavior.

vegetative

Social stimuli—that is, the effects of other people—are weak ____, unless they induce exercise or other vigorous activity.

zeitgebers