Question 1

Which of the following best describes a motor unit?

Accepted Answer

A motor neuron and all the extrafusal muscle fibers it innervates

Question 2

What is the primary function of gamma ($$ \gamma ) $$motor neurons?

Accepted Answer

To control the sensitivity of muscle spindles by innervating intrafusal fibers

Question 3

During a muscle contraction, which of the following is TRUE regarding motor unit recruitment?

Accepted Answer

Small motor units are recruited first, followed by larger ones as more force is needed

Question 4

Which of the following best explains why eye muscles have a low innervation ratio?

Accepted Answer

They need precise, fine control of movement

Question 5

A patient has difficulty sensing limb position but can still generate normal muscle force. Which structure is most likely impaired?

Accepted Answer

Intrafusal muscle fibers (muscle spindles)

Question 6

Which of the following statements about action potentials is correct?

Accepted Answer

Action potentials occur only if the membrane potential reaches threshold

Question 7

If a muscle requires a rapid increase in force, which of the following neural strategies is most likely to occur?

Accepted Answer

Increase the firing rate of already active motor units and recruit additional larger motor units

Question 8

Which of the following best describes the role of extrafusal muscle fibers?

Accepted Answer

They are responsible for generating the force required for movement

Question 9

A researcher is studying the effect of axon diameter on conduction velocity. According to the study materials, which relationship is correct?

Accepted Answer

Larger axon diameter results in faster conduction velocity

Question 10

Which of the following is TRUE regarding the distribution of muscle fibers within a single motor unit?

Accepted Answer

They are distributed throughout the muscle and mixed with fibers from other motor units

Question 11

Which of the following best describes the function of the muscle spindle?

Accepted Answer

To detect changes in muscle length and provide proprioceptive information

Question 12

A person is performing a fine motor task, such as threading a needle. Which of the following characteristics of their motor units is most likely?

Accepted Answer

Low innervation ratio and small motor units

Question 13

Which of the following is a correct statement about the relationship between force and motor unit recruitment?

Accepted Answer

Increasing the number of active motor units increases the force produced by a muscle

Question 14

Which of the following best explains why the same neural activation does not always produce the same muscle force?

Accepted Answer

Muscle properties such as length and velocity influence force output

Question 15

Which of the following is TRUE about the innervation of muscle fibers?

Accepted Answer

Each muscle fiber is innervated by only one motor neuron

Question 16

Which of the following best describes the function of alpha ($$ \alpha ) $$motor neurons?

Accepted Answer

They innervate extrafusal muscle fibers and control muscle contraction

Question 17

A muscle is contracting at a very high velocity. According to the force-velocity relationship, what happens to the force produced?

Accepted Answer

Force decreases as velocity increases during concentric contractions

Question 18

Which of the following is a key difference between extrafusal and intrafusal muscle fibers?

Accepted Answer

Extrafusal fibers are responsible for generating force, while intrafusal fibers are specialized for sensing muscle length

Question 19

Which of the following best describes the concept of 'innervation ratio'?

Accepted Answer

The number of muscle fibers innervated by a single motor neuron

Question 20

A person is unable to generate sufficient force during a muscle contraction, even though all motor units are recruited. Which of the following is the most likely explanation?

Accepted Answer

The muscle is shortening at a very high velocity, reducing force output

Control of Muscle: Motor Units, Neurons, and Muscle Fibres in Motor Control

Guida di studio - Domande di pratica

Study guide - Flashcard