Chapter 10_The Motor System

Question 1

Primary Motor Cortex (M1)

Answer 1

Brain region responsible for executing voluntary movements, located in the precentral gyrus of the frontal lobe.

Question 2

Premotor Cortex

Answer 2

Brain region involved in the planning of movements, especially in response to external stimuli.

Question 3

Supplementary Motor Area (SMA)

Answer 3

Involved in the planning and coordination of complex movements, particularly sequences of internally generated movements.

Question 4

Upper Motor Neurons

Answer 4

Neurons located in the motor cortex that send signals to lower motor neurons in the brainstem or spinal cord to initiate movement.

Question 5

Lower Motor Neurons

Answer 5

Neurons located in the brainstem or spinal cord that directly innervate skeletal muscles to produce movement.

Question 6

Corticospinal Tract

Answer 6

Major motor pathway that carries voluntary movement signals from the motor cortex to the spinal cord, controlling fine motor movements.

Question 7

Lateral Corticospinal Tract

Answer 7

Controls voluntary movements of the limbs, with neurons decussating (crossing over) in the medulla to the opposite side of the body.

Question 8

Anterior Corticospinal Tract

Answer 8

Controls voluntary movements of the trunk and proximal muscles, with some fibers decussating at the spinal cord level.

Question 9

Corticobulbar Tract

Answer 9

Motor pathway that controls muscles of the face, head, and neck by influencing cranial nerves.

Question 10

Basal Ganglia

Answer 10

Group of subcortical structures involved in the initiation, modulation, and inhibition of movements.

Question 11

Caudate Nucleus

Answer 11

Part of the basal ganglia involved in motor processes and learning, particularly in the formation of habits.

Question 12

Putamen

Answer 12

Works with the caudate nucleus to regulate movement and learning, particularly for repetitive or automatic movements.

Question 13

Globus Pallidus

Answer 13

Involved in regulating voluntary movement by inhibiting excessive movement, ensuring smooth motor control.

Question 14

Substantia Nigra

Answer 14

Produces dopamine, crucial for movement control. Degeneration of this structure is associated with Parkinson’s disease.

Question 15

Cerebellum

Answer 15

Brain region involved in coordinating fine motor movements, balance, posture, and motor learning.

Question 16

Vermis

Answer 16

Middle region of the cerebellum responsible for controlling posture and coordinating movements of the trunk.

Question 17

Flocculonodular Lobe

Answer 17

Part of the cerebellum that helps maintain balance and eye movements by interacting with the vestibular system.

Question 18

Deep Cerebellar Nuclei

Answer 18

Nuclei within the cerebellum that send motor output to other parts of the brain, including the dentate nucleus (movement planning) and fastigial nucleus (posture).

Question 19

Central Pattern Generators (CPGs)

Answer 19

Neural circuits in the spinal cord that generate rhythmic, automatic movements such as walking or breathing, without needing sensory input.

Question 20

Motor Unit

Answer 20

A motor neuron and all the muscle fibers it innervates, responsible for muscle contraction.

Question 21

Fast-Twitch Muscle Fibers

Answer 21

Muscle fibers specialized for short bursts of power and speed, but they fatigue quickly.

Question 22

Slow-Twitch Muscle Fibers

Answer 22

Muscle fibers specialized for endurance and continuous activity, highly resistant to fatigue.

Question 23

Skeletal Muscle

Answer 23

Voluntary muscle responsible for body movements, attached to bones and controlled by the somatic nervous system.

Question 24

Smooth Muscle

Answer 24

Involuntary muscle found in the walls of organs and blood vessels, controlled by the autonomic nervous system.

Question 25

Cardiac Muscle

Answer 25

Involuntary, striated muscle found in the heart, responsible for pumping blood, and controlled by its own pacemaker and autonomic input.

Question 26

Spinal Reflex

Answer 26

An automatic motor response generated by the spinal cord in response to sensory input, without requiring input from the brain.

Question 27

Readiness Potential

Answer 27

A measure of brain activity that occurs before a person becomes consciously aware of their decision to move, suggesting the brain initiates movement unconsciously.