Question 1

Which of the following is NOT a primary function of skeletal muscle tissue?

Accepted Answer

Synthesis of hormones for metabolic regulation

Question 2

Which characteristic of skeletal muscle tissue allows it to return to its original length after being stretched or contracted?

Accepted Answer

Elasticity

Question 3

A patient presents with muscle weakness and difficulty maintaining posture. Which function of skeletal muscle is most likely impaired?

Accepted Answer

Stabilization of joints and maintenance of body position

Question 4

Which connective tissue layer surrounds individual muscle fibers and provides electrical insulation?

Accepted Answer

Endomysium

Question 5

During muscle contraction, which protein directly binds to calcium ions to initiate crossbridge cycling?

Accepted Answer

Troponin

Question 6

Which equation best represents the resting membrane potential (RMP) of a skeletal muscle fiber?

Accepted Answer

$$RMP \approx -90\ \mathrm{mV}$$

Question 7

Which of the following best describes the role of the sarcoplasmic reticulum in skeletal muscle contraction?

Accepted Answer

It stores and releases calcium ions required for contraction.

Question 8

A muscle fiber is stimulated and an action potential is generated. What is the correct sequence of events leading to contraction?

Accepted Answer

Release of calcium from SR → Binding of calcium to troponin → Movement of tropomyosin → Crossbridge formation

Question 9

Which of the following structures is the attachment site for thick filaments in the sarcomere?

Accepted Answer

M line

Question 10

Which process is responsible for the removal of acetylcholine from the synaptic cleft during muscle relaxation?

Accepted Answer

Hydrolysis by acetylcholinesterase

Question 11

Which of the following best explains why skeletal muscle fibers are multinucleated?

Accepted Answer

They are formed by the fusion of multiple myoblasts during development.

Question 12

Which of the following is TRUE regarding the role of ATP in crossbridge cycling?

Accepted Answer

ATP is required for the release of the myosin head from actin.

Question 13

A patient with muscular dystrophy is found to have a defect in which structural protein?

Accepted Answer

Dystrophin

Question 14

Which of the following best describes the role of myoglobin in skeletal muscle fibers?

Accepted Answer

It stores oxygen for aerobic ATP production.

Question 15

Which of the following events occurs FIRST during excitation-contraction coupling in skeletal muscle?

Accepted Answer

Generation of an end-plate potential (EPP)

Question 16

Which of the following is a correct description of the A band in a sarcomere?

Accepted Answer

It contains thick filaments and overlapping thin filaments.

Question 17

Which of the following best explains why small motor units allow for precise control of force output?

Accepted Answer

They contain fewer muscle fibers per neuron.

Question 18

Which of the following is TRUE regarding the propagation of an action potential along the sarcolemma?

Accepted Answer

Depolarization is followed by repolarization due to the opening of voltage-gated potassium channels.

Question 19

Which of the following best describes the role of the neuromuscular junction?

Accepted Answer

It is the site where a motor neuron innervates a muscle fiber.

Question 20

Which of the following is the correct sequence for the steps of crossbridge cycling?

Accepted Answer

Crossbridge formation → Power stroke → Release of myosin head → Reset myosin head

Skeletal Muscle: Structure, Function, and Physiology

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