Question 1

The inhibitory feedback mechanism, which allows for muscular relaxation when the opponent muscle is contracting, is lost when one suffers from:

Accepted Answer

Strychnine poisoning blocks inhibitory neurotransmitters like glycine, leading to continuous muscle contraction and loss of the inhibitory feedback mechanism.

Question 2

Central pattern generators can be found in the:

Accepted Answer

Central pattern generators are neural circuits that generate rhythmic motor patterns without sensory input. They are found in the spinal cord and brainstem, and control movements such as walking, swimming, and breathing.

Question 3

The corticospinal tract connects the upper motor neurons to the:

Accepted Answer

The corticospinal tract is a major pathway that connects the upper motor neurons in the brain to the lower motor neurons in the spinal cord, facilitating voluntary motor control.

Question 4

The upper motor neurons are located in the:

Accepted Answer

Upper motor neurons are primarily located in the primary motor cortex, which is responsible for voluntary movement control.

Question 5

If an individual is suffering from cerebral palsy, what difficulty will occur in the motor system?

Accepted Answer

Cerebral palsy is a group of disorders affecting movement and muscle tone, often due to damage to the brain's motor areas. This can disrupt the communication between upper and lower motor neurons, leading to spastic contractions.

Question 6

The Medullary Pyramids are the name for the axon bundles of the corticospinal tract at the levels of the:

Accepted Answer

The Medullary Pyramids are located in the medulla, where the corticospinal tract fibers decussate or cross over.

Question 7

Any axons that do not cross to the contralateral side of the body at the pyramidal decussation form the:

Accepted Answer

The ventral corticospinal tract consists of axons that do not cross at the pyramidal decussation and remain on the same side, eventually crossing at the level of the spinal cord where they synapse.

Question 8

If damage occurred to the rubrospinal tract, disrupting the input from red nuclei, what functions would be effected?

Accepted Answer

The rubrospinal tract is primarily involved in the control of limb movements, particularly the fine motor control of the upper limbs. Damage to this tract would affect the ability to perform precise movements of the limbs.

Question 9

Movements of the limbs would becoming compromised if damage occurred to the _______, disrupting the input from red nuclei.

Accepted Answer

The rubrospinal tract is responsible for transmitting motor signals from the red nucleus to the spinal cord, influencing limb movements. Damage to this tract would disrupt input from the red nuclei, compromising limb movements.

Question 10

Posture and balance would be compromised if damaged occurred to the _____, cutting off input from the vestibular nuclei.

Accepted Answer

The vestibulospinal tract is responsible for maintaining posture and balance by transmitting information from the vestibular nuclei to the spinal cord. Damage to this tract would compromise these functions.

Question 11

If damage occurred to the tectospinal tract, cutting off input from the tectum, what functions would be effected?

Accepted Answer

The answer of If damage occurred to the tectospinal tract,...

Question 12

If damage occurred to the reticulospinal tract, cutting off input from the reticular formation, what functions would be effected?

Accepted Answer

The answer of If damage occurred to the reticulospinal tract,...

Question 13

Startle and escape reflexes would be compromised if damaged occurred to the _____, cutting off input from the reticular formation.

Accepted Answer

The reticulospinal tract is responsible for transmitting signals from the reticular formation to the spinal cord. Damage to this tract would cut off input from the reticular formation, which would compromise startle and escape reflexes.

Question 14

Where can the most greatest number of neurons in the nervous system be found?

Accepted Answer

The cerebellum contains the most neurons in the nervous system, with estimates suggesting it holds about 50% of the total neurons in the brain, despite its smaller size compared to other brain regions.

Question 15

An individual is having great difficulty maintaining balance while walking, and often over-corrects when bumping into an object or person. We can assume that there may be damage to the:

Accepted Answer

The cerebellum is responsible for coordination and balance. Damage to the cerebellum can cause difficulty maintaining balance while walking and over-correcting when bumping into an object or person.

Question 16

An individual is unable to make accurate rapid eye movements, and also seems to have difficulty regulating their speech-They are often changing the volume and rate of their words. We can assume that there may be damage to the:

Accepted Answer

The cerebellum is involved in coordinating voluntary movements, including eye movements and speech regulation. Damage to the cerebellum can lead to difficulties in these areas.

Question 17

Injury to the cerebellum may result in:

Accepted Answer

The cerebellum is responsible for coordinating voluntary movements, including rapid alternating movements, so injury to it can impair these functions.

Question 18

The cerebellum influences the motor activity of upper and lower motor neurons through outputs projected from the:

Accepted Answer

The cerebellum influences motor activity through its outputs from the cerebellar and vestibular nuclei, which project to various motor pathways affecting both upper and lower motor neurons.

Question 19

The cerebellum receives input from the mossy fibers and the:

Accepted Answer

The cerebellum receives input from both mossy fibers and climbing fibers, which are crucial for its role in motor control and coordination.

Question 20

The cerebellum receives input from the climbing fibers and the:

Accepted Answer

The cerebellum receives input from the climbing fibers and the mossy fibers.

Quiz 7: The Motor System