Question 1

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

Accepted Answer

To produce voluntary movements and maintain posture

Question 2

During muscle contraction, which band of the sarcomere shortens, and which remains unchanged?

Accepted Answer

The I band shortens, the A band remains unchanged

Question 3

Which of the following events occurs first at the neuromuscular junction (NMJ) to initiate skeletal muscle contraction?

Accepted Answer

Acetylcholine is released from the motor neuron into the synaptic cleft

Question 4

Which of the following best explains the sliding filament theory of muscle contraction?

Accepted Answer

Actin filaments slide past myosin filaments, shortening the sarcomere

Question 5

A patient is experiencing muscle weakness due to a lack of acetylcholine release at the NMJ. Which step in muscle contraction is directly affected?

Accepted Answer

Transmission of the action potential across the synaptic cleft

Question 6

Which of the following best defines a motor unit?

Accepted Answer

A motor neuron and all the muscle fibers it innervates

Question 7

Which process provides the fastest source of ATP for muscle contraction, but only for a short duration?

Accepted Answer

Creatine phosphate breakdown

Question 8

During intense exercise, when oxygen is limited, which metabolic pathway do muscle cells primarily use to generate ATP, and what is a byproduct?

Accepted Answer

Anaerobic glycolysis; lactic acid

Question 9

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

Accepted Answer

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

Question 10

Which of the following best describes the difference between muscle contraction and muscle relaxation?

Accepted Answer

Contraction involves calcium binding to troponin, while relaxation involves calcium being pumped back into the sarcoplasmic reticulum

Question 11

A muscle is unable to relax after contraction, resulting in a sustained contraction known as tetanus. Which of the following best explains this phenomenon?

Accepted Answer

Continuous stimulation prevents calcium from being reabsorbed into the sarcoplasmic reticulum

Question 12

Which of the following is required for aerobic respiration to efficiently generate ATP in muscle cells?

Accepted Answer

Oxygen and mitochondria

Question 13

Which of the following best describes muscle hypertrophy?

Accepted Answer

Increase in muscle fiber size due to increased protein synthesis

Question 14

Which of the following best defines the term 'origin' in relation to a skeletal muscle?

Accepted Answer

The point where the muscle attaches to the bone that remains stationary during contraction

Question 15

A 70-year-old individual experiences decreased muscle mass and strength. Which of the following best explains this age-related effect on skeletal muscle tissue?

Accepted Answer

Decreased protein synthesis and loss of muscle fibers

Question 16

Which of the following is a homeostatic response of the muscular system to exercise that also affects other body systems?

Accepted Answer

Increased oxygen delivery and removal of carbon dioxide by the cardiovascular and respiratory systems

Question 17

Which of the following steps in muscle contraction directly requires ATP?

Accepted Answer

Detachment of myosin heads from actin filaments

Question 18

A person is running a marathon and relies primarily on aerobic respiration for ATP production. Which of the following is most likely to occur if oxygen supply becomes insufficient?

Accepted Answer

Muscle cells switch to anaerobic glycolysis, resulting in lactic acid accumulation

Question 19

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

Accepted Answer

They bind to troponin, causing tropomyosin to move and expose binding sites on actin

Question 20

Which of the following best explains why ATP is required for both muscle contraction and relaxation?

Accepted Answer

ATP is required to detach myosin heads from actin and to pump calcium ions back into the sarcoplasmic reticulum

Study Guide: The Muscular System (Anatomy & Physiology)

Study Guide - Practice Questions

Study Guide - Flashcards