Chatper 10 Practice

Newborn infants spend as much as _______ % of their sleep time in REM sleep.

50

A woman has just celebrated her 100th birthday. Which description of her sleep is mostly likely to be true?

An EEG of her brain would reveal the complete absence of stage 3 sleep.

Which mechanism has not been identified as a biological function of sleep?

Brain rest

People who tend to wake up in the morning with lots of energy likely carry a different version of the _______ gene than night owls, who stay up late at night and are drowsy in the morning.

Clock

Which statement is about the molecular clock is false?

Clock and Cycle proteins eventually break down and the 24 hour cycle begins again.

What is the primary evolutionary benefit of a circadian rhythm?

It allows an animal to anticipate an important natural event and adjust its behavior accordingly.

What is the significance of the finding that the isolated brain exhibits signs of alternating between wakefulness, SWS, and REM sleep?

It showed that that systems for controlling sleep are located in the brain.

How do dolphins sleep if they must regularly come to the water's surface to breathe?

Only one brain hemisphere sleeps at a time.

Nightmares are associated with _______ sleep.

REM

Flaccidity in the large muscles of the body is associated most commonly with _______ sleep..

REM.

If an adult hamster with a 24-hour endogenous rhythm receives a lesion to the SCN and a subsequent SCN transplant from a young hamster with an endogenous rhythm of 20 hours, which outcome occurs?

The adult hamster will adopt a 20-hour rhythm.

In the U.S., evidence that daylight affects human circadian rhythms is supported by the observation that even though everyone's time keepers (clocks, phone) report the same time, people in the western part of the time zone go to bed _______ people in the in eastern part of the time zone.

a bit later than

When deprived of time cues, people tend to show activity cycles that are

a little more than 24 hours long.

Prolonged sleep deprivation (around 8 days) can lead to all of the following except

a strengthened immune system.

The pattern of sleep in elderly people is characterized by increases in

awakenings.

If a hamster is kept in a laboratory and receives no information about changes in day length or temperature (i.e. housed in constant dark), its rhythms will eventually _______, with a daily cycle that lasts a bit longer than 24 hours.

become free-running

Experimental evidence suggests that the biological role of SWS and REM sleep may be related to the

consolidation of perceptual learning.

Sleep that immediately follows a period of learning has the apparent effect of

improving long-term retention.

The human menstrual cycle provides an example of a(n) _______ rhythm, because it repeats less than once per day.

infradian

Stage 3 sleep (SWS) is especially prominent during the _______ of a night's sleep.

initial half

Norepinephrine innervation to the brain comes primarily from the

locus coeruleus.

If SCN neurons are transplanted from animal A to animal B, and animal B previously had its SCN lesioned, animal B's rhythmicity will

match animal A's rhythm.

The isolated forebrain preparation involves a cut through the

midbrain.

In an experiment with hamsters, if a light with a timer is adjusted so that the light switches on and off 6 hours earlier than the animals are used to, they will show

phase shift.

Unlike in mammals, in birds the _______ is sensitive to light and may mediate entrainment of rhythms even after surgical removal of the eyes.

pineal gland

The region that appears to be responsible for activating wakefulness is known as the

reticular formation.

Infant sleep is characterized by _______ sleep cycles than those of adults, with proportionally more _______ sleep.

shorter; REM

In humans, somnambulism usually occurs during _______ sleep.

stage 3

In a young adult, during the course of a night's sleep the length of the bouts of _______ sleep progressively decrease, while the length of bouts of _______ sleep progressively increase.

stage 3 SWS; REM

In humans, enhanced serum levels of growth hormone are evident during

stage 3 sleep (SWS).

Slow, large-amplitude waves are seen in the EEG records of people who are in _______ sleep..

stage 3.

A child wakes suddenly after sleeping for a couple of hours, is terrified and shows significant autonomic activity, such as a racing heart rate and dilated pupils. When questioned, the child cannot remember what frightened her. It is likely the child has just woken from _______ sleep...

stage 3...

The cortical EEG pattern of the isolated forebrain animal is characterized by

sustained SWS.

A lesion made to the reticular formation will result in a cortical EEG pattern of

sustained sleep.

The sudden attacks of sleep that occur in narcolepsy are characterized by

the immediate onset of REM.

Research has shown that in the forebrain system, SWS is promoted through the actions of GABA on the _______, while in the brainstem system, the _______ projects axons to the brain, promoting wakefulness.

tuberomammillary nucleus; reticular formation

In the typical sleep pattern of healthy adults, the first REM period of the night may last a few minutes while the last REM period may last

up to 40 minutes.

The incidence of insomnia is greatest in _______ in general, and in both men and women in _______.

women; the later stages of life

The stimulus (usually the light-dark cycle) that entrains circadian rhythms is called a(n)

zeitgeber

Depending on the definition used for insomnia, its prevalence ranges from _______ in the adult population.

10% to 40%