9.1 Rhythms Of Waking And Sleeping

Question 0

Research as early as that of _________ implied that the body generates its own cycles of activity and inactivity.

Answer 0

Curt Richter (1922)

Question 1

Your body spontaneously generates its own rhythm of ____ and ____.

Answer 1

wakefulness and sleep

Question 2

Evidently, the bird generates a rhythm that prepares it for seasonal changes. We refer to that rhythm as an ____ ____ ____.

Answer 2

endogenous circannual rhythm

Question 3

Animals also produce ____ ____ ____ that last about a day.

Answer 3

endogenous circadian rhythms

Question 4

The light from the sun helps you feel less sleepy, but also your urge to sleep depends partly on the ________, not just how long you have been awake.

Answer 4

time of day

Question 5

Humans also generate wake-sleep rhythms, and we find it difficult to sleep on anything far from a ________.

Answer 5

24-hour schedule

Question 6

____ ____ affect much more than just waking and sleeping. We have circadian rhythms in our eating and drinking, urination, secretion of hormones, sensitivity to drugs, and other variables.

Answer 6

Circadian rhythms

Question 7

We also have circadian rhythms in ____. In one study, young adults recorded their mood every two hours throughout the day. Most showed increases in positive mood (happiness) from waking until late afternoon, and then a slight decline from then to bedtime.

Answer 7

mood

Question 8

Circadian rhythms differ among individuals. Some people (____ ____, or larks) awaken early, quickly become productive, and become less alert as the day progresses. Others (____ ____, or owls) warm up slowly, reaching their peak in the late afternoon or evening.

Answer 8

morning people : evening people

Question 9

As a child, you went to bed early and woke up early. As an adolescent you started staying up later and waking up later, when you had the opportunity. The mean preferred time of going to sleep gets later and later until about age 20 and then starts a ____ ____.

Answer 9

gradual reversal

Question 10

Our circadian rhythms generate a period close to ______, but they are not perfect. We readjust our internal workings daily to stay in phase with the world.

Answer 10

24 hours

Question 11

Although circadian rhythms persist without light, light is critical for ____ ____. Without something to reset your circadian rhythm, it would gradually drift away from the correct time.

Answer 11

resetting them

Question 12

The stimulus that resets the circadian rhythm is referred to by the German term ____, meaning “time-giver”. Light is the dominant ____ for land animals.

Answer 12

zeitgeber

Question 13

In addition to light, other zeitgebers include____, ____ of any kind, ____, and the ____ of the environment.

Answer 13

exercise, arousal, meals, temperature

Question 14

Social stimuli - that is, the effects of other people - are ____ zeitgebers, unless they induce exercise of other vigorous activity.

Answer 14

weak

Question 15

These additional zeitgebers merely ____ or alter the effects of light. On their own, their effects are weak.

Answer 15

supplement

Question 16

Even when we try to set our wake-sleep cycles by the clock, ____ has its influence. Consider what happens when we shift to daylight savings time in spring.

Answer 16

sunlight

Question 17

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

Answer 17

jet lag

Question 18

Travelers complain of sleepiness during the day, sleeplessness at night, depression, and impaired concentration. All of these problems stem from the mismatch between ___________.

Answer 18

internal circadian clock and external time

Question 19

Most people find it easier to adjust to crossing time zones going _________.

Answer 19

west than east

Question 20

Going west, we stay awake later at night and then awaken late the next morning, already partly adjust to the new schedule. We _____ our circadian rhythms.

Answer 20

phase-delay

Question 21

Going east, we _______ to sleep earlier and awaken earlier. Most people find it difficult to go to sleep before their body’s usual time and difficult to wake up early the next day.

Answer 21

phase-advance

Question 22

Adjusting to jet lag is often stressful. Stress elevates blood levels of the adrenal hormone ____, and many studies have that prolonged elevations of ____ damage neurons in the hippocampus, a brain area important for memory.

Answer 22

cortisol

Question 23

Shift work. People who sleep irregularly - such as pilot, medical interns, and shift workers in factories - find that their ____ of sleep depends on when they go to sleep. When that have to sleep in the morning or early afternoon, they sleep only briefly, even if they have been awake for many hours.

Answer 23

duration

Question 24

Even after months or years on such a schedule, many workers adjust ____. They continue to feel groggy on the job, they sleep poorly during the day, and their body temperature continues to peak when they are sleeping during the day instead of while they are at work during the night.

Answer 24

incompletely

Question 25

People adjust best to night work if they sleep in a ____ ____ room during the day and work under ____ ____ lights at night, comparable to noon day sun.

Answer 25

very dark : very bright