Question 1

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

Accepted Answer

Storing calcium for bone remodeling

Question 2

Which structure within a skeletal muscle fiber is responsible for the striated appearance observed under a microscope?

Accepted Answer

Sarcomere

Question 3

A patient presents with muscle weakness due to a defect in the neuromuscular junction. Which component is most likely malfunctioning if acetylcholine is not being released into the synaptic cleft?

Accepted Answer

Synaptic vesicles in the axon terminal

Question 4

Which of the following best describes the role of ATP during muscle contraction?

Accepted Answer

ATP binds to myosin, causing it to detach from actin

Question 5

During excitation-contraction coupling, which event occurs immediately after an action potential reaches the T-tubule?

Accepted Answer

Release of calcium ions from the sarcoplasmic reticulum

Question 6

A muscle fiber is stimulated at a frequency that does not allow complete relaxation between stimuli, resulting in a sustained, quivering contraction. This phenomenon is best described as:

Accepted Answer

Incomplete tetanus

Question 7

Which equation best represents the breakdown of creatine phosphate to regenerate ATP during short, intense muscle activity?

Accepted Answer

$$\mathrm{Creatine\ phosphate} + \mathrm{ADP} \rightarrow \mathrm{Creatine} + \mathrm{ATP}$$

Question 8

Which of the following factors would NOT increase the peak tension developed during a skeletal muscle contraction?

Accepted Answer

Decreasing the overlap between thick and thin filaments

Question 9

A marathon runner is likely to have a higher proportion of which type of muscle fiber in their leg muscles?

Accepted Answer

Slow oxidative (Type I) fibers

Question 10

Which of the following best explains why muscle fatigue occurs during prolonged, intense exercise?

Accepted Answer

Accumulation of lactic acid and depletion of glycogen stores

Question 11

A patient with a spinal cord injury experiences muscle atrophy. Which physiological process best explains this phenomenon?

Accepted Answer

Lack of neural stimulation leads to decreased protein synthesis in muscle fibers

Question 12

Which of the following best describes an isometric muscle contraction?

Accepted Answer

Muscle tension increases but the muscle does not change length

Question 13

Which of the following is a characteristic of excitable membranes that is essential for generating an action potential in skeletal muscle fibers?

Accepted Answer

Voltage-gated sodium channels that open in response to depolarization

Question 14

Which step occurs FIRST during the contraction cycle of a skeletal muscle fiber?

Accepted Answer

Calcium binds to troponin, causing tropomyosin to move and expose active sites on actin

Question 15

Which of the following best explains the significance of the motor unit in skeletal muscle contraction?

Accepted Answer

It allows for graded control of muscle tension by varying the number of active motor units

Question 16

A weightlifter experiences muscle hypertrophy after months of training. Which cellular change is most responsible for this adaptation?

Accepted Answer

Increased synthesis of contractile proteins (actin and myosin)

Question 17

Which of the following scenarios best illustrates the concept of excitation-contraction coupling?

Accepted Answer

An action potential travels along the sarcolemma, triggering calcium release and muscle contraction

Question 18

Which of the following is TRUE regarding the recovery process after muscle fatigue?

Accepted Answer

Oxygen debt is repaid, and lactic acid is converted back to pyruvate

Question 19

Which of the following best describes the arrangement of thick and thin filaments within a sarcomere?

Accepted Answer

Thick filaments are located in the A band, overlapping with thin filaments in the zone of overlap

Question 20

Which of the following best explains why fast glycolytic (Type IIb) muscle fibers fatigue more quickly than slow oxidative (Type I) fibers?

Accepted Answer

They rely primarily on anaerobic metabolism, which produces less ATP and more lactic acid

Skeletal Muscle Tissue: Structure, Function, and Physiology

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