Question 1

What is responsible for the phenomenon in skeletal muscle known as muscle tone?

Accepted Answer

A)  the passive elastic properties of muscles and joints and some degree of alpha motor neuron activity 
B)  spontaneous entry of calcium into the cytosol and the background phosphorylation of cross-bridges 
C)  depletion of ATP in some individual muscle fibers, and the inability for cross-bridges to detach 
D)  cross-bridges that continuously cycle, even in the absence of cytosolic Ca2+ 
E)  a buildup of K+ in the T-tubules and resulting depolarization of the sarcolemma 
A)  the passive elastic properties of muscles and joints and some degree of alpha motor neuron activity 
B)  spontaneous entry of calcium into the cytosol and the background phosphorylation of cross-bridges 
C)  depletion of ATP in some individual muscle fibers, and the inability for cross-bridges to detach 
D)  cross-bridges that continuously cycle, even in the absence of cytosolic Ca2+ 
E)  a buildup of K+ in the T-tubules and resulting depolarization of the sarcolemma

Question 2

Stretch reflexes:

Accepted Answer

A)  occur only in the legs. 
B)  inhibit antagonistic muscles. 
C)  mediate flexor activation and withdrawal from a painful stimulus. 
D)  are initiated by stimulation of Golgi tendon organs. 
E)  are initiated by stretching of extrafusal muscle fibers. 
A)  occur only in the legs. 
B)  inhibit antagonistic muscles. 
C)  mediate flexor activation and withdrawal from a painful stimulus. 
D)  are initiated by stimulation of Golgi tendon organs. 
E)  are initiated by stretching of extrafusal muscle fibers.

Question 3

What is the function of Golgi tendon organs?

Accepted Answer

A)  They detect stretch within tendons and inhibit the activation of alpha motor neurons to extrafusal muscle fibers in antagonistic muscles. 
B)  They detect painful stimuli within tendons and inhibit gamma motor neurons to intrafusal muscle fibers in muscles attached to those tendons. 
C)  They detect the angle of joints, and thus provide proprioceptive inputs about the position of the limbs in space. 
D)  They detect stretch within tendons and inhibit the activation of alpha motor neurons to extrafusal muscle fibers in the muscle attached to those tendons. 
E)  They stimulate the ends of intrafusal muscle fibers, ensuring that sensory information about muscle length is provided, even when a muscle shortens rapidly. 
A)  They detect stretch within tendons and inhibit the activation of alpha motor neurons to extrafusal muscle fibers in antagonistic muscles. 
B)  They detect painful stimuli within tendons and inhibit gamma motor neurons to intrafusal muscle fibers in muscles attached to those tendons. 
C)  They detect the angle of joints, and thus provide proprioceptive inputs about the position of the limbs in space. 
D)  They detect stretch within tendons and inhibit the activation of alpha motor neurons to extrafusal muscle fibers in the muscle attached to those tendons. 
E)  They stimulate the ends of intrafusal muscle fibers, ensuring that sensory information about muscle length is provided, even when a muscle shortens rapidly.

Question 4

Motor neurons that innervate skeletal muscle fibers are subject to the summative effects of interneurons that release excitatory neurotransmitters and interneurons that release inhibitory neurotransmitters.

Accepted Answer

A) True 
 B)False

Question 5

What occurs when gamma motor neurons to a muscle are activated?

Accepted Answer

A)  The muscle spindle goes slack. 
B)  The contractile ends of intrafusal fibers elongate. 
C)  The muscle lengthens. 
D)  Extrafusal muscle fibers within that muscle are inhibited from contracting. 
E)  Action potential firing increases in afferent neurons from the muscle spindles. 
A)  The muscle spindle goes slack. 
B)  The contractile ends of intrafusal fibers elongate. 
C)  The muscle lengthens. 
D)  Extrafusal muscle fibers within that muscle are inhibited from contracting. 
E)  Action potential firing increases in afferent neurons from the muscle spindles.

Question 6

Afferent information about body movement is in part integrated at the level of the interneurons controlling the firing of alpha motor neurons.

Accepted Answer

A) True 
 B)False

Question 7

When a person steps on a tack with the left foot, flexor muscles on the right leg and extensor muscles on the left leg will be stimulated to contract.

Accepted Answer

A) True 
 B)False

Question 8

Why do people with Parkinson disease experience resting tremors?

Accepted Answer

A)  Damage to the cerebellum alternately activates agonist/antagonist muscle pairs. 
B)  Excess glutamate is released in the premotor areas of the motor cortex. 
C)  Dopamine-secreting tumors directly activate alpha motor neurons. 
D)  Acetylcholinesterase at neuromusclular junctions is inactivated. 
E)  Activation of the sensorimotor cortex is reduced when the substantia nigra fails to deliver dopamine to the basal nuclei. 
A)  Damage to the cerebellum alternately activates agonist/antagonist muscle pairs. 
B)  Excess glutamate is released in the premotor areas of the motor cortex. 
C)  Dopamine-secreting tumors directly activate alpha motor neurons. 
D)  Acetylcholinesterase at neuromusclular junctions is inactivated. 
E)  Activation of the sensorimotor cortex is reduced when the substantia nigra fails to deliver dopamine to the basal nuclei.

Question 9

Which best describes an event that occurs as part of the crossed-extensor reflex?

Accepted Answer

A)  It stimulates contraction of the contralateral flexor and inhibits contraction of the contralateral extensor. 
B)  It stimulates contraction of the contralateral extensor and inhibits contraction of the contralateral flexor. 
C)  It is initiated by stretch in the ipsilateral extensor muscle. 
D)  Inhibitory interneurons are activated, which synapse onto contralateral extensor muscles. 
E)  Monosynaptic excitatory stimulation of ipsilateral extensor muscles occurs. 
A)  It stimulates contraction of the contralateral flexor and inhibits contraction of the contralateral extensor. 
B)  It stimulates contraction of the contralateral extensor and inhibits contraction of the contralateral flexor. 
C)  It is initiated by stretch in the ipsilateral extensor muscle. 
D)  Inhibitory interneurons are activated, which synapse onto contralateral extensor muscles. 
E)  Monosynaptic excitatory stimulation of ipsilateral extensor muscles occurs.

Question 10

Which of the following does NOT describe the highest hierarchical level of motor control?

Accepted Answer

A)  It creates a "motor program" that uses afferent information to generate a pattern of neural activity required to carry out a given action. 
B)  It involves brain regions that include the sensorimotor and cortical association areas. 
C)  It sends signals along "command neurons" to parts of the brain that make up the middle level of the motor control hierarchy. 
D)  It involves brain regions that function in memory, emotions, and motivation. 
E)  It initiates consciously planned movements. 
A)  It creates a "motor program" that uses afferent information to generate a pattern of neural activity required to carry out a given action. 
B)  It involves brain regions that include the sensorimotor and cortical association areas. 
C)  It sends signals along "command neurons" to parts of the brain that make up the middle level of the motor control hierarchy. 
D)  It involves brain regions that function in memory, emotions, and motivation. 
E)  It initiates consciously planned movements.

Question 11

Which of the following statements about control of body movement is FALSE?

Accepted Answer

A)  The corticospinal motor pathways control most fine, discrete muscle activity. 
B)  The brainstem pathways control postural and most other coordinated body movements. 
C)  The cerebellum fine-tunes ongoing movement and helps to coordinate movements. 
D)  The corticobulbar pathways begin in the sensorimotor cortex and end in the brainstem. 
E)  The corticospinal tracts from the right sensorimotor cortex control movements of limbs on the right side of the body. 
A)  The corticospinal motor pathways control most fine, discrete muscle activity. 
B)  The brainstem pathways control postural and most other coordinated body movements. 
C)  The cerebellum fine-tunes ongoing movement and helps to coordinate movements. 
D)  The corticobulbar pathways begin in the sensorimotor cortex and end in the brainstem. 
E)  The corticospinal tracts from the right sensorimotor cortex control movements of limbs on the right side of the body.

What is responsible for the phenomenon in skeletal muscle known as muscle tone?

Stretch reflexes:

What is the function of Golgi tendon organs?

Motor neurons that innervate skeletal muscle fibers are subject to the summative effects of interneurons that release excitatory neurotransmitters and interneurons that release inhibitory neurotransmitters.

What occurs when gamma motor neurons to a muscle are activated?

Afferent information about body movement is in part integrated at the level of the interneurons controlling the firing of alpha motor neurons.

When a person steps on a tack with the left foot, flexor muscles on the right leg and extensor muscles on the left leg will be stimulated to contract.

Why do people with Parkinson disease experience resting tremors?

Which best describes an event that occurs as part of the crossed-extensor reflex?

Which of the following does NOT describe the highest hierarchical level of motor control?

Which of the following statements about control of body movement is FALSE?

Homeostasis: a Framework for Human Physiology

Chemical Composition of the Body and Its Relation to Physiology

Cellular Structure, Proteins, and Metabolic Pathways

Movement of Molecules Across Cell Membranes

Cell Signaling in Physiology

Neuronal Signaling and the Structure of the Nervous System

Sensory Physiology

Consciousness, the Brain, and Behavior

Muscle

The Endocrine System

Cardiovascular Physiology

Respiratory Physiology

The Kidneys and Regulation of Water and Inorganic Ions

The Digestion and Absorption of Food

Regulation of Organic Metabolism and Energy Balance

Reproduction

The Immune System

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Exam 10: Control of Body Movement

What is responsible for the phenomenon in skeletal muscle known as muscle tone?

Stretch reflexes:

What is the function of Golgi tendon organs?

Motor neurons that innervate skeletal muscle fibers are subject to the summative effects of interneurons that release excitatory neurotransmitters and interneurons that release inhibitory neurotransmitters.

What occurs when gamma motor neurons to a muscle are activated?

Afferent information about body movement is in part integrated at the level of the interneurons controlling the firing of alpha motor neurons.

When a person steps on a tack with the left foot, flexor muscles on the right leg and extensor muscles on the left leg will be stimulated to contract.

Why do people with Parkinson disease experience resting tremors?

Which best describes an event that occurs as part of the crossed-extensor reflex?

Which of the following does NOT describe the highest hierarchical level of motor control?

Which of the following statements about control of body movement is FALSE?

Homeostasis: a Framework for Human Physiology

Chemical Composition of the Body and Its Relation to Physiology

Cellular Structure, Proteins, and Metabolic Pathways

Movement of Molecules Across Cell Membranes

Cell Signaling in Physiology

Neuronal Signaling and the Structure of the Nervous System

Sensory Physiology

Consciousness, the Brain, and Behavior

Muscle

The Endocrine System

Cardiovascular Physiology

Respiratory Physiology

The Kidneys and Regulation of Water and Inorganic Ions

The Digestion and Absorption of Food

Regulation of Organic Metabolism and Energy Balance

Reproduction

The Immune System

Filters