Question 1

Which property of muscle tissue allows it to respond to chemical signals released from nerve cells?

Accepted Answer

Excitability

Question 2

A patient is unable to maintain posture and experiences frequent falls. Which function of muscle tissue is most directly impaired?

Accepted Answer

Stabilization

Question 3

Which connective tissue layer directly surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 4

Which type of muscle tissue is striated, involuntary, and contains intercalated discs?

Accepted Answer

Cardiac muscle

Question 5

A toxin blocks the release of acetylcholine at the neuromuscular junction. What is the most likely result?

Accepted Answer

Muscle paralysis

Question 6

Which of the following best describes the role of calcium ions ($$\mathrm{Ca$$^{2+}$$}) in $$skeletal muscle contraction?

Accepted Answer

They bind to troponin, causing tropomyosin to expose myosin binding sites on actin.

Question 7

Which of the following is a correct sequence of events for muscle contraction according to the sliding filament model?

Accepted Answer

Nerve stimulus → ACh release → Ca$$^{2+}$$ release → Actin-myosin binding → Sarcomere shortening

Question 8

A patient with myasthenia gravis has muscle weakness due to loss of function at which site?

Accepted Answer

Acetylcholine receptors on the muscle fiber membrane

Question 9

Which muscle tissue type is most resistant to fatigue and is found in the walls of hollow organs?

Accepted Answer

Smooth muscle

Question 10

Which protein acts as a 'switch' to regulate the exposure of myosin binding sites on actin filaments?

Accepted Answer

Troponin

Question 11

During muscle contraction, which event occurs immediately after acetylcholine binds to its receptor on the muscle fiber membrane?

Accepted Answer

Release of Ca$$^{2+}$$ from the sarcoplasmic reticulum

Question 12

Which of the following best explains why botulinum toxin can be fatal?

Accepted Answer

It blocks acetylcholine release, resulting in paralysis of respiratory muscles.

Question 13

Which structure is the functional unit of striated muscle contraction and is defined as the region between two successive Z discs?

Accepted Answer

Sarcomere

Question 14

A muscle fiber is described as multinucleated, striated, and under voluntary control. Which type of muscle is this?

Accepted Answer

Skeletal muscle

Question 15

Which of the following drugs would be most effective in treating curare poisoning?

Accepted Answer

Neostigmine

Question 16

Which of the following best describes the arrangement of actin and myosin in skeletal muscle fibers?

Accepted Answer

Arranged in parallel bundles, giving a striated appearance

Question 17

A patient presents with muscle spasms and rigidity after a puncture wound. Which bacterial toxin is most likely responsible, and what is its mechanism?

Accepted Answer

Tetanus toxin; blocks inhibitory neurotransmitter release

Question 18

Which of the following best explains why skeletal muscle fibers contain many mitochondria?

Accepted Answer

To provide ATP for sustained muscle contraction

Question 19

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

Accepted Answer

Presence of intercalated discs

Question 20

Which of the following statements about aging and muscle tissue is correct?

Accepted Answer

Skeletal muscle is gradually replaced by fat beginning at age 30.

Muscle Tissue: Structure, Function, and Physiology

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