Question 1

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

Accepted Answer

Secreting hormones

Question 2

Which connective tissue layer directly surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 3

A muscle fiber is considered multinucleate because:

Accepted Answer

It forms by the fusion of myoblasts during development

Question 4

Which of the following best describes the role of the sarcoplasmic reticulum (SR) in muscle contraction?

Accepted Answer

It stores and releases calcium ions

Question 5

During the sliding-filament theory of muscle contraction, which of the following occurs?

Accepted Answer

The Z lines move closer together

Question 6

Which protein binds calcium ions to initiate the contraction cycle in skeletal muscle?

Accepted Answer

Troponin

Question 7

A patient is experiencing muscle weakness due to a lack of acetylcholine (ACh) release at the neuromuscular junction. Which step of muscle contraction is directly affected?

Accepted Answer

Depolarization of the sarcolemma

Question 8

Which of the following best explains why rigor mortis occurs after death?

Accepted Answer

Calcium ions build up in the cytosol and ATP is depleted

Question 9

A muscle fiber is stimulated repeatedly at a frequency that does not allow complete relaxation between stimuli. What is this phenomenon called?

Accepted Answer

Wave summation

Question 10

Which type of muscle contraction occurs when a person tries to lift a heavy object but the muscle does not change length?

Accepted Answer

Isometric

Question 11

Which metabolic pathway provides the most ATP for sustained, low-intensity exercise?

Accepted Answer

Aerobic metabolism

Question 12

Which muscle fiber type is most resistant to fatigue and why?

Accepted Answer

Slow fibers, because they have many mitochondria and high myoglobin content

Question 13

A marathon runner’s muscles are primarily composed of which type of muscle fiber?

Accepted Answer

Slow fibers

Question 14

Which of the following is a unique structural feature of cardiac muscle cells compared to skeletal muscle fibers?

Accepted Answer

Intercalated discs

Question 15

Which of the following best describes the role of titin in the sarcomere?

Accepted Answer

It helps restore sarcomere length after contraction

Question 16

Which of the following is TRUE regarding smooth muscle tissue?

Accepted Answer

It contracts in response to Ca2+ binding to calmodulin

Question 17

A patient with a genetic defect in the protein nebulin would most likely have problems with:

Accepted Answer

Holding F-actin strands together in thin filaments

Question 18

Which of the following best explains why muscle hypertrophy occurs after resistance training?

Accepted Answer

Increase in the diameter of muscle fibers and number of myofibrils

Question 19

Which of the following is a consequence of muscle atrophy?

Accepted Answer

Reduction in muscle size, tone, and power

Question 20

Which of the following best describes the relationship between load and speed of contraction in skeletal muscle?

Accepted Answer

The heavier the load, the slower the contraction

Muscle Tissue: Structure, Function, and Contraction Mechanisms

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