Question 1

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.
A) upper motor
B) lower motor
C) preganglionic
D) postganglionic
E) somesthetic

Accepted Answer

Lower motor neurons have their cell bodies within the spinal cord and directly innervate skeletal muscle fibers. Upper motor neurons have their cell bodies in the brain and synapse with lower motor neurons in the spinal cord. Preganglionic and postganglionic neurons are involved in the autonomic nervous system, and somesthetic neurons are involved in sensory information for touch, pressure, and temperature.

Question 2

Figure 13-4 The Corticospinal Pathway
Use Figure 13-4 to answer the following questions:
-Identify the origin of the axon labeled "2."
A) lower motor neuron
B) upper motor neuron
C) decussation neuron
D) second-order neuron
E) ganglionic neuron

Accepted Answer

Axon labeled "2" originates from an upper motor neuron in the primary motor cortex.

Question 3

Axons of the corticobulbar tract terminate in the
A) sensory neurons.
B) somatic motor neurons in the spinal cord.
C) autonomic motor neurons in the spinal cord.
D) motor nuclei of cranial nerves.
E) nuclei in the thalamus.

Accepted Answer

Axons of the corticobulbar tract terminate in the motor nuclei of cranial nerves. This pathway is responsible for the voluntary control of the muscles of the face, head, and neck.

Question 4

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts.
A) corticospinal
B) corticobulbar
C) reticulospinal
D) vestibulospinal
E) tectospinal

Accepted Answer

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the corticospinal tracts, which originate from the motor cortex and control voluntary movement of the limbs and trunk.

Question 5

Tracts of the lateral and medial pathways include all of the following, except ________ tracts.
A) corticospinal
B) tectospinal
C) rubrospinal
D) reticulospinal
E) vestibulospinal

Accepted Answer

The answer of Tracts of the lateral and medial pathways...

Question 6

Figure 13-4 The Corticospinal Pathway
Use Figure 13-4 to answer the following questions:
-Identify the structure labeled "5."
A) ventral root
B) upper motor neuron
C) first-order neuron
D) second-order neuron
E) dorsal root

Accepted Answer

The answer of  
Figure 13-4 The Corticospinal Pathway
Use Figure...

Question 7

Damage to the pyramidal cells of the cerebral cortex would directly affect
A) perception of pain.
B) sight.
C) voluntary motor activity.
D) hearing.
E) both perception of pain and voluntary motor activity.

Accepted Answer

The pyramidal cells of the cerebral cortex are responsible for voluntary motor activity, so damage to these cells would directly affect this function. Perception of pain, sight, and hearing are controlled by other areas of the brain.

Question 8

The upper motor neurons of the medial pathway are located within any of the following, except the
A) vestibular nuclei.
B) reticular formation.
C) superior colliculi.
D) inferior colliculi.
E) mamillary bodies.

Accepted Answer

The upper motor neurons of the medial pathway are located in the vestibular nuclei, reticular formation, superior colliculi, and red nucleus, but not in the mamillary bodies.

Question 9

The area of the motor cortex that is devoted to a particular region of the body is proportional to the
A) size of the body area.
B) distance of the body area from the brain.
C) number of motor units in that region.
D) number of sensory receptors in the area of the body.
E) size of the nerves that serve the area of the body.

Accepted Answer

The area of the motor cortex that is devoted to a particular region of the body is proportional to the number of motor units in that region. This means that areas of the body that require more precise and complex movements, such as the hands and face, have a larger representation in the motor cortex than areas that require more basic movements, such as the legs.

Question 10

Each of the following is an ascending tract in the spinal cord, except the
A) fasciculus gracilis.
B) fasciculus cuneatus.
C) posterior spinocerebellar.
D) reticulospinal tract.
E) anterior spinothalamic.

Accepted Answer

All other options are ascending tracts, meaning they carry sensory information up to the brain. The reticulospinal tract is a descending tract, meaning it carries motor commands down from the brain to the spinal cord.

Question 11

Axons that decussate between the pyramids of the medulla oblongata belong to the ________ tracts.
A) anterior corticospinal
B) lateral corticospinal
C) vestibulospinal
D) reticulospinal
E) rubrospinal

Accepted Answer

The lateral corticospinal tracts are the axons that decussate at the pyramids of the medulla oblongata before descending down the spinal cord. A is incorrect because the anterior corticospinal tracts do not decussate until they reach the level of the spinal cord. C is incorrect because the vestibulospinal tracts do not decussate at the pyramids, but rather in the lower brainstem. D is incorrect because the reticulospinal tracts also do not decussate at the pyramids, but rather in the spinal cord itself. E is incorrect because the rubrospinal tracts decussate at the level of the midbrain, not the medulla oblongata.

Question 12

Damage to the tectospinal tracts would interfere with the
A) ability to position the arms.
B) ability to monitor body position.
C) ability to make reflex responses of the head and neck in response to sudden movements or loud noises.
D) ability to control motor units located in the leg.
E) ability to coordinate eating and swallowing movements.

Accepted Answer

The tectospinal tracts are responsible for reflex responses of the head and neck in response to sudden movements or loud noises, so damage to this tract would interfere with this ability.

Question 13

Damage to the pyramidal cells of the cerebral cortex would directly affect
A) perception of pain.
B) sight.
C) voluntary motor activity.
D) hearing.
E) both perception of pain and hearing.

Accepted Answer

The pyramidal cells of the cerebral cortex are responsible for voluntary motor activity. Damage to these cells would directly affect the ability to control and initiate movement.

Question 14

Figure 13-4 The Corticospinal Pathway
Use Figure 13-4 to answer the following questions:
-Identify the structure labeled "1" in this neural pathway.
A) primary sensory cortex
B) primary motor cortex
C) thalamus
D) autonomic motor center
E) basal nuclei

Accepted Answer

Structure labeled "1" is the primary motor cortex, which initiates voluntary movement by sending signals down the corticospinal pathway.

Question 15

Conscious and subconscious motor commands control skeletal muscles by traveling over the
A) corticospinal pathway.
B) medial pathway.
C) lateral pathway.
D) all of the above
E) none of the above

Accepted Answer

All of the pathways mentioned (corticospinal, medial, and lateral) are involved in transmitting motor commands to control skeletal muscles.

Question 16

Descending (motor) pathways always involve at least ________ motor neuron(s).
A) one
B) two
C) three
D) four
E) spinal

Accepted Answer

Descending motor pathways always involve at least two motor neurons: an upper motor neuron that descends from the cerebral cortex or brainstem to the spinal cord or brainstem, and a lower motor neuron that goes from the spinal cord or brainstem to the muscle fibers.

Question 17

Identify the type of information that travels along the structure labeled "4."
A) motor commands to skeletal muscles
B) proprioception to the cerebral cortex
C) fine touch to the cerebral cortex
D) pain and crude touch sensations
E) visceral motor commands to smooth muscle

Accepted Answer

Structure labeled "4" represents the corticospinal tract, which carries motor commands from the cerebral cortex to skeletal muscles. Therefore, the type of information that travels along this pathway is motor commands to skeletal muscles.

Question 18

A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?
A) corticospinal tract
B) tectospinal tract
C) rubrospinal tract
D) corticobulbar tract
E) reticulospinal tract

Accepted Answer

The corticobulbar tract is responsible for the voluntary movement of the face and is a major pathway for the control of the facial muscles. Damage to this tract can result in facial paralysis.

Question 19

What occurs in this neural pathway at label "3"?
A) synapse
B) communication between sensory and motor neurons
C) amplification of motor signals
D) decussation
E) autonomic reflexes

Accepted Answer

Label "3" represents the point of decussation, where the majority of nerve fibers cross over from one side of the body to the other.

Question 20

The corticospinal system is often referred to as the
A) red nucleus.
B) reticular formation.
C) spinothalamic tracts.
D) pyramidal system.
E) medullary centers.

Accepted Answer

The corticospinal system refers to the group of neural pathways that originate in the cortex of the brain and descend through the spinal cord. It is also known as the pyramidal system, as the fibers cross over at the level of the medulla oblongata, creating a distinctive shape resembling a pyramid. The other options listed are not associated with the corticospinal system.

Quiz 13: The Brain and Cranial Nerves

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.

Figure 13-4 The Corticospinal Pathway Use Figure 13-4 to answer the following questions: -Identify the origin of the axon labeled "2."

Axons of the corticobulbar tract terminate in the

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts.

Tracts of the lateral and medial pathways include all of the following, except ________ tracts.

Figure 13-4 The Corticospinal Pathway Use Figure 13-4 to answer the following questions: -Identify the structure labeled "5."

Damage to the pyramidal cells of the cerebral cortex would directly affect

The upper motor neurons of the medial pathway are located within any of the following, except the

The area of the motor cortex that is devoted to a particular region of the body is proportional to the

Each of the following is an ascending tract in the spinal cord, except the

Axons that decussate between the pyramids of the medulla oblongata belong to the ________ tracts.

Damage to the tectospinal tracts would interfere with the

Damage to the pyramidal cells of the cerebral cortex would directly affect

Figure 13-4 The Corticospinal Pathway Use Figure 13-4 to answer the following questions: -Identify the structure labeled "1" in this neural pathway.

Conscious and subconscious motor commands control skeletal muscles by traveling over the

Descending (motor) pathways always involve at least ________ motor neuron(s) .

Identify the type of information that travels along the structure labeled "4."

A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?

What occurs in this neural pathway at label "3"?

The corticospinal system is often referred to as the