Question 1

The medial pathway of the indirect motor pathway consists of three groups of tracts.The one that helps to regulate positional changes of the arms,eyes,head,and neck as a consequence of visual and auditory stimuli is the

Accepted Answer

The tectospinal tract helps regulate the positional changes of the arms, eyes, head, and neck in response to visual and auditory stimuli. The reticulospinal and vestibulospinal tracts have other functions such as controlling posture and balance.

Question 2

In motor pathways,axons of lower motor neurons exit the _________ and project to the __________ to be innervated.

Accepted Answer

Lower motor neurons are located in the spinal cord and brainstem, which are part of the central nervous system (CNS). The axons of these neurons exit the CNS and project to the skeletal muscles in the periphery of the body (not sensory receptors). Therefore, the correct choices are A and B. However, B is not the best choice as it includes the term PNS, which refers to the peripheral nervous system as a whole (including sensory receptors), while only the skeletal muscles are targeted in this case.

Question 3

Complex unconscious motor patterns are controlled by neurons in various locations.The ones that control swinging the arms while walking are located in the

Accepted Answer

The cerebral nuclei, also known as basal ganglia, are involved in the control of voluntary motor movements, procedural learning, routine behaviors or habits (like swinging the arms while walking), eye movements, cognition, and emotion. These functions make the cerebral nuclei crucial for complex unconscious motor patterns.

Question 4

Axons of the lower motor neurons of the lateral corticospinal tracts innervate

Accepted Answer

The lateral corticospinal tracts are responsible for controlling voluntary movement in the limbs. The lower motor neurons of these tracts innervate skeletal muscles that control skilled movements in the limbs, such as those involved in manipulating objects and walking. Therefore, option A is the correct choice. The other options are incorrect because they involve muscles that are not innervated by the lateral corticospinal tracts.

Question 5

The different tracts within indirect motor pathways are grouped according to their primary functions.The medial pathway regulates

Accepted Answer

The medial pathway, which includes the vestibulospinal and reticulospinal tracts, is primarily responsible for regulating muscle tone and gross movements of the muscles of the head, neck, proximal limb, and trunk. This pathway helps to maintain posture and balance, and is important for activities such as walking and standing upright.

Question 6

The medial pathway of the indirect motor pathway consists of three groups of tracts.The one that helps to control unskilled automatic movements related to posture and maintaining balance is the

Accepted Answer

The answer of The medial pathway of the indirect motor...

Question 7

Which somatic motor pathway originates in the pyramidal cells of the primary motor cortex?

Accepted Answer

The direct pathway, also known as the corticospinal tract, originates in the pyramidal cells of the primary motor cortex and travels directly to the spinal cord to control voluntary movements. The indirect pathway, on the other hand, involves multiple synapses and circuits before reaching the target muscles.

Question 8

The different tracts within indirect motor pathways are grouped according to their primary functions.The lateral pathway controls

Accepted Answer

The lateral pathway includes the corticospinal and rubrospinal tracts, which are responsible for controlling precise, discrete movements and tone in flexor muscles of the limbs.

Question 9

In order to assess voluntary movements,messages from proprioceptors in skeletal muscles and joints are forwarded to the

Accepted Answer

Proprioceptors in skeletal muscles and joints send information about voluntary movements to the cerebellum, which is responsible for coordinating and refining these movements. The basal nuclei and the primary cortex also play a role in voluntary movement, but they do not receive direct input from proprioceptors. The brainstem regulates automatic movements and reflexes, but it does not play a major role in voluntary movements. The corpus callosum is primarily involved in communication between the two hemispheres of the brain and does not play a direct role in voluntary movements.

Question 10

The corticobulbar tracts originate from the ______ region of the motor homunculus within the primary cortex.

Accepted Answer

The corticobulbar tracts originate from the facial region of the motor homunculus within the primary cortex. The term "bulbar" refers to the brainstem, specifically the cranial nerve nuclei. Thus the corticobulbar tracts are a collection of nerve fibers that begin in the motor cortex and descend to synapse onto cranial nerves in the brainstem that control movements of the face, head, and neck.

Question 11

A child pounding on the keys of a piano makes a cacophony of unrecognizable noise,whereas a trained pianist reproduces a Mozart sonata.The portion of the brain that controls and coordinates the movements necessary to play the piano is the

Accepted Answer

The cerebellum is responsible for coordinating and controlling movement, including the fine motor movements required to play the piano. Therefore, it is the best choice for the portion of the brain that controls and coordinates piano playing. The thalamus and diencephalon are involved in sensory processing and relaying information, while the medulla oblongata regulates autonomic functions such as breathing and heart rate. The corpus callosum connects the two hemispheres of the brain and is not directly involved in movement control.

Question 12

Complex unconscious motor patterns are controlled by neurons in various locations.The ones that control activities such as riding a bicycle are located in the

Accepted Answer

The cerebellum is responsible for the coordination and fine-tuning of complex unconscious motor patterns, such as riding a bicycle. The mesencephalon, hypothalamus, cerebral nuclei and medulla oblongata are involved in other functions such as sensory processing, regulation of autonomic functions, and control of voluntary movements.

Question 13

Motor pathways are formed from a series of connections.Which is not part of the series?

Accepted Answer

The hypothalamus is not a direct part of the motor pathway series, as it is primarily involved in regulating basic physiological functions and behaviors, rather than directly controlling muscle movement. The other choices (A, B, D, and E) are all important components of the motor pathway series, with the cerebellum and cerebral nuclei involved in motor coordination and regulation, descending projection tracts conveying signals from the brain to the spinal cord, and motor neurons transmitting signals from the spinal cord to muscles.

Question 14

Complex unconscious motor patterns are controlled by neurons in various locations.The ones that control sudden startled movements due to visual or auditory stimuli are located in the

Accepted Answer

The mesencephalon, also known as the midbrain, contains nuclei related to the control of motor movements, including sudden movements due to visual or auditory stimuli. This region is also involved in other functions such as eye movement and regulation of pain.

Question 15

The medial pathway of the indirect motor pathway consists of three groups of tracts.The one that helps to regulate muscular activity that helps maintain balance during sitting,standing,and walking is the

Accepted Answer

The vestibulospinal tract is responsible for regulating muscular activity that helps maintain balance during sitting, standing, and walking. The reticulospinal tract is involved in regulating posture and muscle tone, while the tectospinal tract is involved in reflexive head movements in response to visual and auditory stimuli.

Question 16

The pair of thick anterior bulges (pyramids)in the medulla oblongata are formed by the

Accepted Answer

The pair of thick anterior bulges in the medulla oblongata are known as pyramids and are formed by the corticospinal tracts. These tracts originate from the motor cortex in the brain and descend through the internal capsule, brainstem, and spinal cord to control voluntary movements of the body.

Question 17

Which somatic motor pathway is responsible for voluntary control of muscle activity?

Accepted Answer

The direct pathway, also known as the pyramidal pathway or corticospinal pathway, is responsible for voluntary control of muscle activity. It originates in the cerebral cortex and travels through the brainstem and spinal cord to synapse with motor neurons that control skeletal muscles. The indirect pathway, on the other hand, is involved in involuntary control of muscle activity and includes several subcortical structures such as the basal ganglia and cerebellum.

Question 18

Of the four indirect motor spinal cord pathways that originate in the brainstem,the one whose upper motor neuron destination is the lateral funiculus is the

Accepted Answer

The rubrospinal tract originates in the red nucleus of the midbrain and its fibers cross to the opposite side of the midbrain before descending into the spinal cord through the lateral funiculus. This tract is involved in motor control, particularly in facilitating flexor muscles and inhibiting extensor muscles.

Question 19

Axons of the lower motor neurons of the anterior corticospinal tracts innervate

Accepted Answer

The anterior corticospinal tracts primarily innervate axial skeletal muscles, which are responsible for controlling the trunk and proximal limb muscles.

Question 20

Which of these movements or muscle groups is not controlled by motor information transmitted by the corticobulbar tracts?

Accepted Answer

The corticobulbar tracts are responsible for controlling the skeletal muscles of the face, head and neck, but not the muscles of the upper legs. Eye movements, certain superficial muscles of the back and neck, cranial, facial, pharyngeal, and laryngeal muscles, as well as intrinsic and extrinsic muscles of the tongue are all controlled by the corticobulbar tracts.

Quiz 17: Pathways and Integrative Functions