Question 1

Which of the following is a property shared by all muscle tissue types?

Accepted Answer

Ability to contract forcibly when stimulated

Question 2

A patient presents with muscle weakness and frequent falls. Genetic testing reveals a mutation in the gene encoding dystrophin. Which condition is most likely?

Accepted Answer

Duchenne muscular dystrophy

Question 3

During muscle contraction, which event directly allows myosin heads to bind to actin?

Accepted Answer

Binding of Ca^{2+} to troponin

Question 4

Which equation correctly represents the direct phosphorylation of ADP by creatine phosphate in muscle cells?

Accepted Answer

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

Question 5

Which muscle fiber type is best suited for maintaining posture over long periods?

Accepted Answer

Slow oxidative fibers

Question 6

A muscle is stimulated repeatedly at a high frequency, resulting in a smooth, sustained contraction with no relaxation. What is this phenomenon called?

Accepted Answer

Fused (complete) tetanus

Question 7

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

Accepted Answer

It stores and releases Ca^{2+} ions

Question 8

A marathon runner’s leg muscles are found to have increased numbers of mitochondria and capillaries after months of training. Which adaptation is most likely responsible for this change?

Accepted Answer

Aerobic (endurance) exercise

Question 9

Which of the following is TRUE regarding the length-tension relationship in skeletal muscle?

Accepted Answer

Maximum force is generated when sarcomeres are at 80–120% of their resting length

Question 10

Which process is responsible for the propagation of an action potential along the sarcolemma?

Accepted Answer

Sequential opening of voltage-gated Na^+ channels

Question 11

Which of the following is a structural difference between cardiac and skeletal muscle cells?

Accepted Answer

Cardiac muscle cells are connected by intercalated discs

Question 12

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

Accepted Answer

Ionic imbalances and accumulation of inorganic phosphate interfere with contraction

Question 13

Which equation represents the net ATP yield from aerobic respiration of one glucose molecule in muscle cells?

Accepted Answer

$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\mathrm{O}_2 \rightarrow 6\mathrm{CO}_2 + 6\mathrm{H}_2\mathrm{O} + 32\mathrm{ATP}$

Question 14

Which of the following is TRUE about smooth muscle contraction compared to skeletal muscle contraction?

Accepted Answer

Smooth muscle contraction involves calmodulin binding to Ca^{2+}

Question 15

A weightlifter is performing a biceps curl. As the muscle shortens and lifts the weight, which type of contraction is occurring?

Accepted Answer

Isotonic concentric contraction

Question 16

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

Accepted Answer

They transmit action potentials deep into the muscle fiber

Question 17

Which of the following is a function of muscle tone in skeletal muscles?

Accepted Answer

It keeps muscles firm, healthy, and ready to respond

Question 18

Which of the following is TRUE regarding multiunit smooth muscle?

Accepted Answer

It consists of independent muscle fibers innervated by the autonomic nervous system

Question 19

A patient is unable to move a limb after nerve damage. Over time, the muscle decreases in size and is replaced by connective tissue. What is this process called?

Accepted Answer

Atrophy

Muscles & Muscle Tissue: Structure, Function, and Physiology

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