$$\mathrm{ATP} \rightarrow \mathrm{ADP} + \mathrm{P_i} + \text{energy}$$

Question 1

Which of the following best describes the primary function of skeletal muscle tissue?

Accepted Answer

To transform chemical energy (ATP) into mechanical energy for movement

Question 2

Which of the following is a unique characteristic of cardiac muscle tissue compared to skeletal and smooth muscle?

Accepted Answer

Presence of intercalated discs

Question 3

A muscle fiber is stimulated by a motor neuron. Which structure transmits the action potential deep into the muscle fiber?

Accepted Answer

Transverse (T) tubule

Question 4

Which of the following best explains why muscle tone is important for the human body?

Accepted Answer

It keeps muscles firm, stabilizes joints, and maintains posture

Question 5

During the sliding filament model of contraction, which event directly causes the sarcomere to shorten?

Accepted Answer

Myosin heads bind to actin and pull thin filaments toward the M line

Question 6

Which of the following is the correct sequence of events in the generation of an action potential in a muscle fiber?

Accepted Answer

End plate potential → Depolarization → Repolarization

Question 7

A patient is unable to relax their muscles after death, resulting in rigor mortis. What is the primary cause of this phenomenon?

Accepted Answer

Lack of ATP to detach myosin heads from actin

Question 8

Which of the following equations correctly represents the hydrolysis of ATP during muscle contraction?

Accepted Answer

$$\mathrm{ATP} ightarrow \mathrm{ADP} + \mathrm{P_i} + 	ext{energy}$$

Question 9

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

Accepted Answer

It stores and releases calcium ions to trigger contraction

Question 10

A muscle is contracting but does not change in length. What type of contraction is this?

Accepted Answer

Isometric

Question 11

Which of the following is true regarding the recruitment of motor units during muscle contraction?

Accepted Answer

Small motor units are recruited first, followed by larger ones as more force is needed

Question 12

Which of the following best explains why wave (temporal) summation increases muscle tension?

Accepted Answer

It increases the frequency of action potentials, causing more Ca$$^{2+} to $$accumulate in the cytosol

Question 13

Which of the following muscle fiber types is most resistant to fatigue and best suited for endurance activities?

Accepted Answer

Slow oxidative fibers

Question 14

Which of the following is a direct result of increased recruitment during a muscle contraction?

Accepted Answer

Increased number of muscle fibers contracting

Question 15

A marathon runner relies primarily on which pathway for ATP generation during prolonged exercise?

Accepted Answer

Aerobic respiration

Question 16

Which of the following best describes the relationship between muscle length and tension generation?

Accepted Answer

Maximum force is generated when the muscle is between 80% and 120% of its resting length

Question 17

Which of the following is a likely cause of muscle fatigue during intense exercise?

Accepted Answer

Ionic imbalances and increased inorganic phosphate

Question 18

Which of the following is the correct formula for the anaerobic conversion of glucose to lactate in muscle fibers?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} \rightarrow 2\ \mathrm{C_3H_6O_3} + 2\ \mathrm{ATP}$$

Question 19

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

Accepted Answer

It binds to Ca$$^{2+}$$, causing tropomyosin to move and expose myosin binding sites on actin

Muscles and Muscle Tissue: Structure, Function, and Contraction

Study Guide - Practice Questions