Question 1

Which connective tissue layer directly surrounds individual skeletal muscle fibers?

Accepted Answer

Endomysium

Question 2

During muscle contraction, which ion is released from the sarcoplasmic reticulum to initiate the process?

Accepted Answer

Calcium ($Ca^{2+}$)

Question 3

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

Accepted Answer

Acetylcholine

Question 4

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

Accepted Answer

Sarcomere

Question 5

Which protein forms the thick filaments in a sarcomere?

Accepted Answer

Myosin

Question 6

A patient is unable to maintain body temperature after exposure to cold. Which function of skeletal muscle is most directly impaired?

Accepted Answer

Maintenance of body temperature

Question 7

Which structure is a specialized form of smooth endoplasmic reticulum that stores calcium ions in skeletal muscle fibers?

Accepted Answer

Sarcoplasmic reticulum

Question 8

Which connective tissue layer surrounds a muscle fascicle?

Accepted Answer

Perimysium

Question 9

Which of the following is NOT a function of skeletal muscle?

Accepted Answer

Production of lymphocytes

Question 10

In the sliding filament theory, what happens to the sarcomere during muscle contraction?

Accepted Answer

The sarcomere shortens

Question 11

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

Accepted Answer

Troponin binds calcium ions, causing tropomyosin to shift and expose actin binding sites

Question 12

A motor unit consists of:

Accepted Answer

A motor neuron and all the muscle fibers it innervates

Question 13

Which of the following is TRUE regarding the organization of skeletal muscle?

Accepted Answer

The endomysium surrounds individual muscle fibers

Question 14

Which of the following is the correct sequence for the events of muscle contraction?

Accepted Answer

Calcium released → Troponin shifts tropomyosin → Actin exposed → Myosin binds actin → Sarcomere shortens

Question 15

Which of the following is a real-life example of an antagonistic muscle pair?

Accepted Answer

Biceps brachii and triceps brachii during elbow flexion and extension

Question 16

Which of the following best describes the role of the neuromuscular junction?

Accepted Answer

It is the site where axons of motor neurons communicate with muscle fibers

Question 17

If a motor neuron innervates 100 muscle fibers, what is the size of the motor unit?

Accepted Answer

100

Question 18

Which of the following is TRUE about the structure of a myofibril?

Accepted Answer

It is composed of repeating units called sarcomeres

Question 19

Which of the following is a synergist muscle during elbow flexion?

Accepted Answer

Brachioradialis

Question 20

Which equation best represents the relationship between force ($F$), cross-sectional area ($A$), and muscle tension ($T$) in skeletal muscle?

Accepted Answer

$F = T 	imes A$

The Muscular System: Structure, Function, and Organization

Study Guide - Practice Questions