Chapter 8

Question 1

What evidence indicates that humans have an internal biological clock?

Answer 1

People who have lived in an environment with a light–dark schedule much different from 24 hours fail to follow that schedule and instead become wakeful and sleepy on about a 24-hour basis.

Question 2

Why do people at the eastern edge of Germany awaken earlier than those at the western edge on their weekends and holidays?

Answer 2

The sun rises about half an hour earlier at the eastern edge than at the western edge. Evidently, the sun controls waking–sleeping schedules even when people follow the same clock time for their work schedule.

Question 3

What evidence strongly indicates that the SCN produces the circadian rhythm itself?

Answer 3

SCN cells produce a circadian rhythm of activity even if they are kept in cell culture isolated from the rest of the body. Also, when hamsters received transplanted SCN neurons, their circadian rhythm followed the pattern of the donor animals.

Question 4

How does light reset the biological clock?

Answer 4

A branch of the optic nerve, the retinohypothalamic path, conveys information about light to the SCN. The axons comprising that path originate from special ganglion cells that respond to light by themselves, even if they do not receive input from rods or cones.

Question 5

Someone who is blind because of cortical damage can still synchronize his or her circadian rhythm to the local pattern of day and night. Why?

Answer 5

If the retina is intact, melanopsin-containing ganglion cells can still send messages to the SCN, resetting its rhythm.

Question 6

How do the proteins TIM and PER relate to sleepiness in Drosophila?

Answer 6

The proteins TIM and PER remain low during most of the day and begin to increase toward evening. They reach high levels at night, promoting sleep. They also feed back to inhibit the genes that produce them, so that their level declines toward morning.

Question 7

self-generated rhythm that lasts about a day

Answer 7

endogenous circadian rhythms

Question 8

self-generated rhythm that lasts about a year

Answer 8

endogenous circannual rhythm

Question 9

a disruption of circadian rhythms due to crossing time zones

Answer 9

jet lag

Question 10

hormone that influences both circadian and circannual rhythms

Answer 10

melatonin

Question 11

an endocrine gland located just posterior to the thalamus that releases the hormone melatonin

Answer 11

pineal gland

Question 12

part of the hypothalamus; provides the main control of the circadian rhythms for sleep and body temperature

Answer 12

suprachiasmatic nucleus (SCN)

Question 13

stimulus that resets the circadian rhythm

Answer 13

zeitgeber

Question 14

Animals, including humans, have circadian rhythms—internally generated rhythms of activity and sleep lasting about 24 hours, even in an unchanging environment. It is difficult to adjust to a sleep schedule much different from 24 hours.
True or False?

Answer 14

True

Question 15

Although the biological clock continues to operate in constant light or constant darkness, the onset of light resets the clock. Even when people set their waking and sleeping times by the clock, the timing of sunrise strongly influences their circadian rhythm.
True or False?

Answer 15

True

Question 16

It is easier for most people to follow a cycle longer than 24 hours (as when traveling west) than to follow a cycle shorter than 24 hours (as when traveling east).
True or False?

Answer 16

True

Question 17

If people wish to work at night and sleep during the day, the best way to shift the circadian rhythm is to have bright lights at night and darkness during the day.
True or false?

Answer 17

True

Question 18

Some people are most alert early in the morning, and others become more alert later in the day. On average, people around 20 years old show the greatest preference for staying awake late and sleeping late the next morning.
True or False?

Answer 18

True

Question 19

The suprachiasmatic nucleus (SCN), a part of the hypothalamus, generates the body’s circadian rhythms for sleep and temperature.
True or False?

Answer 19

True

Question 20

Light resets the biological clock partly by a branch of the optic nerve that extends to the SCN. Those axons originate from a special population of ganglion cells that respond directly to light in addition to receiving some input from rods and cones.
True or False?

Answer 20

True

Question 21

The genes controlling the circadian rhythm are almost the same in mammals as in insects. Circadian rhythms result from a feedback cycle based on genes that produce the proteins PER and TIM, and the ability of those proteins to inhibit the genes that produce them.
True or false?

Answer 21

True

Question 22

The SCN controls the body’s rhythm partly by directing the release of melatonin by the pineal gland. The hormone melatonin increases sleepiness; if given at certain times of the day, it can also reset the circadian rhythm.
True or false?

Answer 22

True

Question 23

What conclusion do researchers draw from the observation that workers on submarines are unable to adjust to a schedule of working 12 hours and resting 6 hours?

Answer 23

The human body generates a circadian rhythm.

Question 24

Why do people in Antarctica during the winter often find it difficult to work together?

Answer 24

Their circadian rhythms drift out of phase with one another.

Question 25

If workers rotate between working shifts at different times of day, what would be a good way to help them adjust to the night shift?

Answer 25

Use bright lighting during the night shift.

Question 26

What tends to be characteristic of teenagers who are extreme "evening" types?

Answer 26

They get worse grades in school than their abilities would predict.

Question 27

What evidence strongly indicates that the SCN produces the circadian rhythm itself?

Answer 27

SCN cells isolated from the body continue to produce a circadian rhythm.

Question 28

Light resets the biological clock by a branch of the optic nerve, beginning with ________ and sending the input to ________ .

Answer 28

ganglion cells that do not require input from rods or cones . . . the SCN

Question 29

If you want to get to sleep on time, what should you avoid?

Answer 29

Short-wavelength light late in the evening

Question 30

The proteins Tim and Per reach their highest levels ________ . They ________ the activity of the genes that produce them.

Answer 30

at night... inhibit

Question 31

What conclusion do researchers draw from the observation that workers on submarines are unable to adjust to a schedule of working 12 hours and resting 6 hours?

Answer 31

The human body generates a circadian rhythm

Question 32

What do large, slow waves on an EEG indicate?

Answer 32

Large, slow waves indicate a low level of activity, with much synchrony of response among neurons.

Question 33

How can an investigator determine whether a sleeper is in REM sleep?

Answer 33

Examine EEG pattern and eye movements.

Question 34

During which part of a night’s sleep is REM most common?

Answer 34

REM becomes more common toward the end of the night’s sleep.

Question 35

Why do most antihistamines make people drowsy?

Answer 35

Two paths from the hypothalamus—one to the basal forebrain and one to the pontomesencephalon—use histamine as their neurotransmitter to increase arousal. Antihistamines that cross the blood–brain barrier block those synapses.

Question 36

What would happen to the sleep–wake schedule of someone who lacked orexin?

Answer 36

Someone without orexin would alternate between brief periods of waking and sleeping.

Question 37

Physiology recording instruments measure all of the following except

Answer 37

emotional state

Question 38

If you choose to measure galvanic skin response, you should

Answer 38

attach the unit to the subject's ring finger and pointer finger

Question 39

Biofeedback can lead to a subject gaining a greater awareness of their body's physiological functions with the goal of learning to control the body system at will. True or False?

Answer 39

True

Question 40

What is biofeedback?

Answer 40

A technique people can use to learn to control their body's physiological responses

Question 41

Biofeedback appeals to many people because it is:

Answer 41

can allow an individual to elminate the need for certain medications

Question 42

Biofeedback allows a subject to____certain muscles to achieve the wanted results, such as relieving pain.

Answer 42

relax

Question 43

How long does a typical biofeedback session last?

Answer 43

30-60 minutes

Question 44

If you choose to measure ECG, you should

Answer 44

use an alcholol swab to clean the area before applying an electrode.

Question 45

Has to do with pitch?

Answer 45

Frequency

Question 46

Has to do with loudness?

Answer 46

amplitude

Question 47

The higher frequencies are processed by the _______ portion of the auditory cortex

Answer 47

Posterior

Question 48

New estimates put the rate of synesthesia at approximately what proportion of adults?

Answer 48

1/23

Question 49

Muscles are composed of many individual____

Answer 49

fibers

Question 50

Each muscle fiber receives info from ___axon

Answer 50

only one

Question 51

Axon may innervate ___muscle fibers

Answer 51

many

Question 52

synapse between a motor neuron axon and a muscle fiber

Answer 52

neuromuscular junction

Question 53

Movement requires the alternating contraction of | opposing sets of muscles called _____

Answer 53

antagonistic muscles

Question 54

Acetylcholine always excites skeletal muscles to | contract. True or False?

Answer 54

True

Question 55

A ____ muscle is one that flexes or raises an | appendage: i.e., biceps

Answer 55

flexor

Question 56

An _____muscle is one that extends an | appendage or straightens it: i.e., triceps

Answer 56

extensor

Question 57

Slow-twitch fibers are *aerobic* and require oxygen | during movement and therefore do not fatigue during _____ activities

Answer 57

Nonstrenuous

Question 58

Fast-twitch fibers are *anaerobic* and use reactions that do not require oxygen, resulting in fatigue from behaviors requiring quick movements or ____activities

Answer 58

strenuous

Question 59

receptors that detect the position or | movement of a part of the body

Answer 59

Proprioceptors

Question 60

proprioceptors parallel to the | muscle that responds to a stretch which causes a contraction of the muscle

Answer 60

Muscle spindles

Question 61

``` ____occurs when muscle proprioceptors detect the stretch and tension of a muscle and send messages to the spinal cord to contract it ```

Answer 61

Stretch reflex

Question 62

What neurotransmitter is responsible for skeletal muscle contraction?

Answer 62

Acetylcholine

Question 63

This type of muscle would | straighten an appendage:

Answer 63

Extensor

Question 64

-another type of proprioceptor that responds to increases in muscle tension -Located in the tendons at the opposite ends of the muscle ``` -Acts as a “brake” against excessively vigorous contraction by sending an impulse to the spinal cord where motor neurons are inhibited ```

Answer 64

Golgi tendon organ

Question 65

Most movement is a combination of planned and | ___-

Answer 65

reflex

Question 66

We move faster in response to a ___ than when we | decide on our own

Answer 66

stimulus

Question 67

movements that once initiated, cannot be altered or corrected Example: stretch reflex, dilation of the pupil

Answer 67

Ballistic movements

Question 68

- located in the precentral gyrus located in the frontal lobe - active when people intend a movement - “orders” an outcome

Answer 68

primary motor cortex

Question 69

-keeps track of the position of the body relative to the world -Damage to this area causes difficulty in coordinating visual stimuli with movement -Important for planning movement

Answer 69

Posterior parietal cortex

Question 70

-Responds to lights, noises, and other sensory signals that lead to movement -Calculates predictable outcomes of actions and plans movement according to those outcomes

Answer 70

Prefrontal cortex

Question 71

- Active during preparation for movement - Receives information about a target - Integrates information about position and posture of the body; organizes the direction of the movement in space

Answer 71

Premotor cortex

Question 72

-Organizes rapid sequence of movements in a specific order; inhibitory if necessary -Active seconds before the movement

Answer 72

Supplementary motor cortex

Question 73

Areas in the cortex that are active both when making a movement and when watching someone else make a movement

Answer 73

Mirror Neurons

Question 74

- structure in the brain often associated with balance and coordination - Majority of brain’s neurons - Damage to it causes trouble with rapid movements requiring aim/timing. Examples: clapping hands, speaking, writing, etc. -Studies suggest that it is important for the establishment of new motor programs that allow the execution of a sequence of actions as a whole - Important for tasks that require timing - seems critical for certain aspects of attention, such as the ability to shift attention and attend to *visual stimuli* -receives input from the spinal cord, from each of the sensory systems and the cerebral cortex, and sends it to the cerebellar cortex

Answer 74

cerebellum

Question 75

The cerebellar cortex is the surface of the | ____

Answer 75

cerebellum

Question 76

Cerebellar cortex neurons are arranged in ___ geometrical patterns. Regular pattern allows outputs of well-controlled duration

Answer 76

precise

Question 77

Neurons that are flat parallel cells in sequential planes in cerebral cortex

Answer 77

Purkinje cells

Question 78

Axons in the cerebral cortex that are parallel to one another; perpendicular to planes of Purkinje cells

Answer 78

Parallel fibers

Question 79

The greater the number of excited ___, the | greater their collective duration of response

Answer 79

Purkinje cells

Question 80

Parallel fibers excite ____ cells.

Answer 80

Purkinje

Question 81

____transmit inhibitory messages to the cells in the nuclei of the cerebellum (clusters of cell bodies in the interior of the cerebellum) and the vestibular nuclei in the brain stem -Messages then sent to the midbrain and the thalamus

Answer 81

Purkinje cells

Question 82

Which area would plan and calculate outcomes of | complex motor tasks?

Answer 82

Premotor cortex

Question 83

Which area would be most involved in attention to visual stimuli and attention shifting?

Answer 83

Cerebellum

Question 84

- group of large subcortical structures in the forebrain - Responsible for initiating an action not guided by a stimulus ``` -Comprised of the following structures: • Caudate nucleus • Putamen • Globus pallidus ```

Answer 84

basal ganglia

Question 85

___ nucleus and putamen receive input from the cerebral cortex and send output to the globus pallidus

Answer 85

Caudate

Question 86

Globus pallidus connects to the thalamus, which relays information to the motor areas and the prefrontal cortex which Inhibits the ___

Answer 86

thalamus

Question 87

_____ select a movement to make by ceasing to inhibit it

Answer 87

Basal ganglia

Question 88

The learning of new skills requires____ brain | areas involved in the control of movement

Answer 88

multiple

Question 89

-critical for learning motor skills, organizing sequences of movement, “automatic” behaviors, and new habits • Example: driving a car, riding a bike -Relevant neurons in the motor cortex also increase their firing rate; the pattern of activity becomes more consistent as the skill is learned

Answer 89

Basal Ganglia

Question 90

Movement disorder characterized by muscle tremors, rigidity, slow movements, and difficulty initiating physical and mental activity -Impairment in initiating spontaneous movement -Symptoms also include depression, memory and reasoning deficits, loss of olfaction, cognitive deficits -Death of neurons in substantia nigra, which sends dopamine releasing axons to caudate nucleus and putamen ``` -Influences • Genetic link • Toxins that destroy dopamine producing neurons • Drugs • Pesticides • Damaged mitochondria ``` -Decreased risk: cigarettes and coffee Treatment: • L-dopa • Precursor to dopamine • Unpleasant side effects

Answer 90

Parkinson’s Disease

Question 91

Genetic based neurological disorder characterized by various motors symptoms • Affects 1 in 10,000 in the United States • Usually onset occurs between age 30-50 • Associated with gradual and extensive brain damage especially in the caudate nucleus, putamen, globus pallidus, and the cerebral cortex Initial motor symptoms include arm jerks and facial twitches • Motors symptoms progress to tremors and writhing that affect the persons walking, speech, and other voluntary movements • Also associated with various psychological disorders: • Depression, memory impairment, anxiety, hallucinations/delusions, poor judgment, alcoholism, drug abuse, sexual disorders Presymptomatic tests can identify with high accuracy who will develop the disease • Controlled by an autosomal dominant gene on chromosome #4 • The higher the number of consecutive repeats of the combination C-A-G, the more certain and earlier the person is to develop the disease

Answer 91

Huntington’s Disease