Question 1

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

Accepted Answer

Troponin binds to calcium ions, causing a conformational change that moves tropomyosin and exposes active sites on actin.

Question 2

A patient is unable to maintain posture and body position after a spinal cord injury. Which function of skeletal muscle is most directly affected?

Accepted Answer

Maintenance of posture and body position

Question 3

During muscle contraction, which of the following changes occur according to the sliding filament theory?

Accepted Answer

The H band and I band get smaller.

Question 4

Which property of muscle tissue allows it to return to its original length after being stretched or contracted?

Accepted Answer

Elasticity

Question 5

A marathon runner's leg muscles are dominated by which type of muscle fiber, and why?

Accepted Answer

Slow fibers, because they are resistant to fatigue and use aerobic metabolism.

Question 6

Which of the following best explains why skeletal muscle contraction requires ATP?

Accepted Answer

ATP is required for the detachment of myosin heads from actin during the cross-bridge cycle.

Question 7

A muscle that assists the prime mover in performing an action is called a:

Accepted Answer

Synergist

Question 8

Which of the following statements about muscle hypertrophy is correct?

Accepted Answer

Hypertrophy is caused by an increase in the number of mitochondria and myofibrils within muscle fibers.

Question 9

Which lever system in the human body magnifies force but moves the resistance more slowly and over a shorter distance?

Accepted Answer

Second-class lever

Question 10

A muscle is described as having its origin on a broad aponeurosis and its insertion on a narrow tendon. Which of the following is true?

Accepted Answer

The aponeurosis is the origin and the tendon is the insertion.

Question 11

Which of the following best describes the arrangement of thick and thin filaments in a sarcomere?

Accepted Answer

Thick and thin filaments are organized in parallel arrays with sarcomeres lying side by side.

Question 12

Which of the following events occurs first during skeletal muscle contraction?

Accepted Answer

An action potential travels along the sarcolemma.

Question 13

A muscle that produces extension at a joint is classified as which of the following?

Accepted Answer

Antagonist to the flexor

Question 14

Which of the following best explains why muscle atrophy occurs after prolonged disuse?

Accepted Answer

There is a decrease in myofibrils and muscle fiber diameter.

Question 15

Which muscle fiber type is most likely to be found in high concentrations in the deltoid muscle of a sprinter?

Accepted Answer

Fast fibers (white fibers)

Question 16

Which of the following is a characteristic of a third-class lever in the human body?

Accepted Answer

The applied force is between the fulcrum and the resistance.

Question 17

A patient with a genetic defect in myoglobin production would most likely have impaired function in which muscle fiber type?

Accepted Answer

Slow fibers

Question 18

Which of the following best describes the function of muscle tone?

Accepted Answer

It stabilizes the position of bones and joints by producing resting tension.

Question 19

Which of the following is true regarding the effect of aging on skeletal muscle?

Accepted Answer

The ability to recover from muscular injuries decreases.

Question 20

A muscle is named 'biceps brachii.' According to anatomical terminology, what does 'biceps' indicate?

Accepted Answer

The muscle has two origins.

The Muscular System—Skeletal Muscle Tissue and Organization

Study Guide - Practice Questions