$$3\ \mathrm{Na^+}\ \text{out},\ 2\ \mathrm{K^+}\ \text{in}$$

Question 1

Which of the following is a key difference between skeletal, cardiac, and smooth muscle tissue?

Accepted Answer

Skeletal muscle is voluntary and striated, cardiac muscle is involuntary and striated, and smooth muscle is involuntary and nonstriated.

Question 2

Which structure stores calcium ions that are essential for muscle contraction in skeletal muscle fibers?

Accepted Answer

Sarcoplasmic reticulum

Question 3

During the sliding filament model of muscle contraction, which protein forms cross-bridges with actin?

Accepted Answer

Myosin

Question 4

What is the primary neurotransmitter released at the neuromuscular junction to stimulate skeletal muscle contraction?

Accepted Answer

Acetylcholine

Question 5

Which equation best represents the sodium-potassium pump activity that maintains the resting membrane potential in muscle cells?

Accepted Answer

$$3\ \mathrm{Na^+}\ 	ext{out},\ 2\ \mathrm{K^+}\ 	ext{in}$$

Question 6

Which process is responsible for the rapid depolarization phase of the action potential in muscle fibers?

Accepted Answer

Influx of $$\mathrm{Na^+}$$ ions through voltage-gated channels

Question 7

Which of the following best describes temporal summation in skeletal muscle contraction?

Accepted Answer

Increasing the frequency of stimulation to produce a stronger contraction

Question 8

Which metabolic pathway provides the fastest source of ATP for muscle contraction?

Accepted Answer

Direct phosphorylation of ADP by creatine phosphate

Question 9

A patient with Duchenne muscular dystrophy (DMD) is most likely to have a defect in which protein?

Accepted Answer

Dystrophin

Question 10

Which of the following is a possible cause of muscle fatigue during prolonged exercise?

Accepted Answer

Accumulation of lactic acid in muscle fibers

Question 11

Which type of muscle contraction occurs when the muscle changes length while generating force?

Accepted Answer

Isotonic contraction

Question 12

Which factor does NOT directly influence the force of skeletal muscle contraction?

Accepted Answer

The color of the muscle tissue

Question 13

Which of the following best explains why smooth muscle is able to sustain contractions for longer periods than skeletal muscle?

Accepted Answer

Smooth muscle uses less ATP and has slower cross-bridge cycling

Question 14

Which equation represents the aerobic breakdown of glucose for ATP production in muscle cells?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\ \mathrm{O_2$} \rightarrow 6\ \mathrm{CO_2$} + 6\ \mathrm{H_2O} + 36\ \mathrm{ATP}$$

Question 15

Which adaptation is most likely to occur in skeletal muscle after several weeks of resistance exercise?

Accepted Answer

Increase in muscle fiber diameter (hypertrophy)

Question 16

Which of the following best describes the role of troponin in muscle contraction?

Accepted Answer

Troponin binds calcium ions, causing tropomyosin to move and expose myosin binding sites on actin.

Question 17

Which event marks the beginning of excitation-contraction coupling in skeletal muscle?

Accepted Answer

Release of calcium ions from the sarcoplasmic reticulum

Question 18

Which of the following is a real-world consequence of administering vecuronium to a patient without proper monitoring?

Accepted Answer

Paralysis of respiratory muscles leading to respiratory arrest

Question 19

Which of the following best explains the phenomenon of rigor mortis?

Accepted Answer

Sustained cross-bridge formation due to lack of ATP after death

Question 20

Which of the following is a critical safety consideration when administering neuromuscular blocking agents in a clinical setting?

Accepted Answer

Ensuring proper airway management and monitoring respiratory function

Muscles and Muscle Tissue: Structure, Function, and Physiology (Chapter 9 Study Guide)

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