Deck 13: Integrative Physiology I: Control of Body Movement

Question 1

The "normal" contractile fibers of the muscle are also called the

A) extrafusal fibers.
B) intrafusal fibers.
C) muscle spindle fibers.

Answer 1

A

Question 2

It is the middle of winter and you walk over an icy patch and lose your balance.As you begin to fall,you react by extending your arms to catch yourself.In this instance,what type of reflex is occurring?

A) stretch reflex
B) tendon reflex
C) flexor reflex
D) crossed extensor reflex
E) reciprocal reflex

Answer 2

D

Question 3

The reflex that complements a withdrawal reflex by making compensatory adjustments on the opposite side of the body receiving the stimulus is the

A) stretch reflex.
B) tendon reflex.
C) flexor reflex.
D) crossed extensor reflex.
E) reciprocal reflex.

Answer 3

D

Question 4

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
several neurons involved in a pathway; can be complex

Question 5

Most reflexes are regulated by

A) the brain.
B) the spinal cord.
C) ganglia.
D) positive feedback.
E) negative feedback.

Question 6

Which is NOT true regarding autonomic reflexes?

A) Vomiting, sneezing, and coughing are all examples of autonomic reflexes.
B) Integrating centers for autonomic reflexes in the brain include the hypothalamus, brain stem, and limbic system.
C) Autonomic reflexes are all monosynaptic, with their synapse in the central nervous system.
D) Many autonomic reflexes are characterized by tonic activity, a continuous stream of action potentials.

Question 7

The reflex that prevents a muscle from exerting too much tension is the

A) stretch reflex.
B) tendon reflex.
C) flexor reflex.
D) crossed extensor reflex.
E) reciprocal reflex.

Question 8

Most reflex movements are integrated by

A) the brain.
B) the spinal cord.
C) central pattern generators.
D) proprioceptors.
E) effectors.

Question 9

Identify the FALSE statement.

A) Adipose tissue is controlled by autonomic efferents.
B) All reflexes require input from the brain.
C) Some reflexes are genetically determined.
D) Muscle spindles are stretch receptors.
E) Proprioceptors detect limb position and movement.

Question 10

The flexion reflex

A) prevents a muscle from overstretching.
B) prevents a muscle from generating damaging tension.
C) moves a limb away from a painful stimulus.
D) makes adjustments in other parts of the body in response to a particular stimulus.
E) is an example of a monosynaptic reflex.

Question 11

The effector in a reflex is the

A) control center.
B) afferent neuron.
C) efferent neuron.
D) sensory receptor.
E) muscle or gland.

Question 12

Interneurons of the corticospinal tract synapse onto

A) visceral efferents.
B) somatic efferents.
C) interneurons of central pattern generators.

Question 13

A polysynaptic reflex has at least ________ in the reflex pathway.

A) one synapse
B) two synapses
C) two neurons
D) three neurons
E) two synapses and three neurons

Question 14

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
integrated in the brain

Question 15

Motor neurons are sometimes inhibited by

A) Golgi tendon organs.
B) muscle spindle organs.
C) joint receptors.

Question 16

Which reflex is NOT controlled by the brain stem?

A) urination
B) vomiting
C) sneezing
D) swallowing
E) salivating

Question 17

The structure whose abnormal function is associated with Parkinson's disease is the

A) spinal cord.
B) basal ganglia.
C) cerebellum.
D) primary motor cortex.
E) skeletal muscle.

Question 18

The sensory fibers of the muscle spindle organs synapse onto

A) Golgi tendon organs.
B) gamma motor neurons.
C) alpha motor neurons.
D) joint receptors.

Question 19

Which class of movement can be considered a combination of the other two?

A) reflex
B) voluntary
C) rhythmic

Question 20

Spinal interneurons prevent muscle antagonists from interfering with an intended movement by

A) initiating a crossed extensor reflex.
B) initiating a stretch reflex.
C) initiating a tendon reflex.
D) the process of reciprocal inhibition.
E) activating reverberating circuits.

Question 21

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
found at the junction of tendons and muscle fibers

Question 22

The tension maintained in a muscle at rest is known as ________.

Question 23

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
involves skeletal muscles

Question 24

Rhythmic reflexive motor activities,such as breathing or walking,are controlled by networks of neurons in the central nervous system called ________.

Question 25

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
reflexes that one is born with; genetically determined

Question 26

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
have afferent neurons that bring information to the CNS

Question 27

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
have gamma motor neurons that innervate internal fibers

Question 28

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
excite both alpha and gamma motor neurons

Question 29

In order to flex a limb,the extensors must first be relaxed and vice versa.This is done by a process called ________.

Question 30

Autonomic reflexes are also called ________ reflexes.

Question 31

________ monitor the position of skeletal muscles and joints.

Question 32

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
eventually synapses with alpha motor neurons that innervate extrafusal muscle fibers

Question 33

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
integrated in the spinal cord,often modulated by the brain

Question 34

Match the structure to its description.
A.muscle spindles
B.Golgi tendon organs
C.both
maintain muscle tone at rest through tonic activity

Question 35

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
our experiences tell us how to behave; bracing yourself in anticipation would be an example

Question 36

Match the type of reflex to its description.
A.somatic
B.autonomic
C.spinal
D.cranial
E.innate
F.acquired
G.polysynaptic
an example would be slowing or speeding the heart and other internal organs that are not consciously controlled

Question 37

________ reflexes involve skeletal muscles.

Question 38

The motor neurons that innervate the normal contractile fibers of the muscle are the ________.

Question 39

The motor neurons associated with intrafusal muscle fibers are referred to as ________ motor neurons.

Question 40

Relaxation of skeletal muscle results from ________ input by the somatic motor neuron.

Question 41

A muscle at rest exerts no tension.Is this statement
Explain your answer.

Question 42

A ________ reflex has at least one interneuron placed between the sensory and motor neuron.

Question 43

After stretching an intrafusal fiber,the next event is

A) an increase in action potentials along the associated sensory neuron.
B) a decrease in muscle tension.
C) a decrease in muscle tone.
D) decreased sensitivity to stretching.
E) All of the answers are correct.

Question 44

How does the stretch reflex protect a muscle?

Question 45

________ allows the body to anticipate a stimulus and begin the response,whereas negative feedback results in the ________ of a response.

Question 46

List three ways that neural reflex pathways can be classified.Name one of the reflexes in each category.What additional information may be gained from the name of the reflex? Name a specific reflex and identify its classification in all of the categories you listed.

Question 47

Ten-year-old Tina falls while climbing a tree and lands on her back.Her frightened parents take her to the local emergency room where she is examined.Her knee jerk reflex is normal and she exhibits a negative Babinski reflex.These results suggest that

A) Tina has injured one of her descending nerve tracts.
B) Tina has injured one of her ascending nerve tracts.
C) Tina has a spinal injury in the lumbar region.
D) Tina has a spinal injury in the cervical region.
E) Tina suffered no damage to her spinal cord.

Question 48

In a ________ reflex,a sensory neuron synapses directly on a motor neuron.

Question 49

You are studying for your physiology test with your lab partner.She insists that the purpose of the knee jerk reflex is to test for neural or muscular damage.State whether or not you agree with her,and why.

Question 50

Muscle spindles are ________ receptors and cause reflex ________,whereas Golgi tendon organs respond primarily to ________ and cause a ________ reflex.

Question 51

What are the three levels of nervous system that control movement? Briefly describe their roles.

Question 52

List and describe the three categories of movement.Explain why these categories are NOT always distinct.

Question 53

The control of voluntary movement can be divided into what three steps?

Question 54

The ________ is essentially a group of interneurons that run from the motor cortex to the spinal cord.

Question 55

Are relaxation of a muscle and inhibition of a muscle the same thing? Explain your answer.

Question 56

Make a map of the following terms: alpha motor neurons,CNS,contractile fibers,extrafusual muscle fibers,Golgi tendon organs,integrating center,joint receptors,muscle spindles,proprioreceptors,sensory neurons,sensory receptors and somatic motor neurons.

Question 57

When there is a resistance to the movement produced by a given limb muscle,

A) gamma motor neurons are inhibited by higher brain centers.
B) there is a decrease in the amount of force generated by extrafusal muscle fibers.
C) the muscle involved in the movement immediately shortens when stimulated.
D) intrafusal fibers receive fewer action potentials from the gamma motor neurons.
E) muscle tone is increased and more motor units are recruited to the contraction.

Question 58

Most reflexes are regulated by ________.

Question 59

Explain alpha-gamma coactivation.

Question 60

The collection of pathways controlling a single joint is known as ________.The simplest reflex in this collection of pathways is the ________,which involves only two neurons: ________ neuron from the ________ and the ________ neuron to the muscle.

Question 61

You are a technician in a neuroanatomy lab,and it's your first day of training to learn a technique of labeling neurons.Your boss tells you that you will fill individual motor neurons,by injecting horseradish peroxidase (HRP)conjugated to tetanus toxin,into a skeletal muscle.How could this possibly label the neurons?

Question 62

A.Ernie,an experienced batter,steps up to the plate,looks off into the distance,and plans where to hit the baseball.He then swings the bat,connects with the ball,sends it into the air,and follows through the swing with his arms,hips,and knees,and shifts his weight from one leg to the other.He watches the ball fly away,and takes off for first base.Explain what areas of the central nervous system are working during each phase of the action outlined,and which step is controlled by each part.
B.Continue to integrate this with information from other topics as the action continues: Ernie hears the umpire yell "Infield fly! Batter's out!" He remembers the rules of the game,slows his pace,and leaves the baseline before arriving at first base.

Question 63

Upon testing the knee jerk reflex during a routine physical,a nurse notices that the reflex is hyperactive.What could be the explanation for this? If instead the reflex was hypoactive,what may the nurse conclude?

Question 64

Draw a diagram of the cerebral motor cortex and descending input to spinal motor neurons.Voluntary suppression of the knee jerk reflex originates in the motor cortex,which can send inhibitory signals to the motor neurons.If the left motor cortex is active,is the left or right knee jerk reflex suppressed or are both suppressed? Explain your answer.If the left side of the spinal cord at the level of leg muscle control is damaged,is it the left or right knee jerk reflex that is suppressed or are both suppressed?

Question 65

Explain how an animal with a paralyzing spinal injury can be induced to walk,though it can't walk on its own.Diagram and label the structures involved.(Hint: Keep it simple; for example,you could draw a rectangle and label it "right leg muscle" and another for the left,and don't worry about drawing all neurons involved,just enough to show you understand the basics.You may wish to start with a simple sketch of a muscle reflex then add on to it as necessary.)

Question 66

Bowel and bladder control involve spinal reflex pathways that are located in the sacral region of the spinal cord.In both instances,two sphincter muscles,an inner sphincter of smooth muscle and an outer sphincter of skeletal muscle,control the passage of waste out of the body.How would completely severing the spinal cord at the lumbar level affect an individual's bowel and bladder control?

Question 67

Two of your physiology classmates are trying to figure out if cross country skiing is a voluntary activity or a rhythmic activity.They come to you to determine who is correct.What do you tell them?

Question 68

While watching Olympic weight lifters on television,Carl notices that on several occasions an athlete would lift the weight to his chest and then suddenly drop it.Can you offer an explanation for what might be happening?

Question 69

Diagram and label the knee jerk reflex.What is the physiological function of this reflex? Explain how this reflex may be important during walking,if you didn't notice a dip in the sidewalk and stepped into it.What is the role of reciprocal inhibition? How would the reflex be affected if reciprocal inhibition failed? Describe the effects on the reflex of severing each structure involved in the reflex,considering one structure at a time.Describe the effects of damaging the opposite side of the spinal cord,or areas higher or lower on the spinal cord.