Question 1

Which of the following best describes the microscopic structure of a skeletal muscle fiber?

Accepted Answer

Elongated, multinucleated cells with visible striations

Question 2

During muscle contraction, which band remains the same width while others change?

Accepted Answer

A-band

Question 3

What is the functional unit of a skeletal muscle fiber responsible for contraction?

Accepted Answer

Sarcomere

Question 4

Which of the following correctly lists the organization of muscle structures from smallest to largest?

Accepted Answer

Myofilament → Myofibril → Muscle fiber → Muscle fascicle → Muscle

Question 5

Which protein is primarily responsible for the thick filaments in the sarcomere?

Accepted Answer

Myosin

Question 6

A motor unit consists of:

Accepted Answer

A single neuron and all the muscle fibers it innervates

Question 7

Which event occurs first at the neuromuscular junction to initiate muscle contraction?

Accepted Answer

Release of acetylcholine from the synaptic terminal

Question 8

Which enzyme is responsible for breaking down acetylcholine in the synaptic cleft?

Accepted Answer

Acetylcholinesterase

Question 9

If a muscle is contracting but its length does not change, what type of contraction is occurring?

Accepted Answer

Isometric contraction

Question 10

During a concentric contraction, which of the following is true?

Accepted Answer

Muscle tension exceeds the load and the muscle shortens

Question 11

Which of the following best explains why muscle fatigue occurs during prolonged activity?

Accepted Answer

Accumulation of metabolic wastes such as lactic acid and depletion of energy sources

Question 12

Which statement about the speed of muscle contraction is correct?

Accepted Answer

The speed of contraction is inversely related to the load

Question 13

Which region of the sarcomere contains only thin filaments?

Accepted Answer

I-band

Question 14

What is the role of the sarcoplasmic reticulum in muscle contraction?

Accepted Answer

It stores and releases calcium ions necessary for contraction

Question 15

Which of the following formulas correctly represents the relationship between force, load, and acceleration in muscle contraction?

Accepted Answer

$F = m 	imes a$

Question 16

A patient is unable to move a heavy object despite maximal muscle contraction. Which type of contraction is most likely occurring?

Accepted Answer

Isometric contraction

Question 17

Which instrument is commonly used to measure static flexibility at a joint?

Accepted Answer

Goniometer

Question 18

Which of the following best describes dynamic flexibility?

Accepted Answer

Range of motion measured with consideration of resistance and ease of movement

Question 19

Which of the following is true regarding motor unit recruitment?

Accepted Answer

Motor units with lower threshold stimuli are recruited first as stimulus strength increases

Question 20

Which of the following best describes tetanus in muscle physiology?

Accepted Answer

A period of smooth, sustained muscle contraction due to rapid stimulation

Introduction to Skeletal Muscle: Structure, Types, and Physiology

Study Guide - Practice Questions