Question 1

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

Accepted Answer

Secreting hormones

Question 2

Which connective tissue layer surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 3

What is the role of the sarcoplasmic reticulum (SR) in skeletal muscle contraction?

Accepted Answer

It stores and releases calcium ions ($$\mathrm{Ca$$^{2+}$$})$$

Question 4

During the sliding filament theory of muscle contraction, which of the following occurs?

Accepted Answer

The Z lines move closer together

Question 5

Which protein binds calcium ions to initiate the exposure of active sites on actin?

Accepted Answer

Troponin

Question 6

A patient is unable to relax their muscles after death, a condition known as rigor mortis. What is the primary cause?

Accepted Answer

Depletion of ATP and accumulation of $$\mathrm{Ca$$^{2+}$$}$$

Question 7

Which of the following best describes an isometric muscle contraction?

Accepted Answer

Muscle develops tension but does not change length

Question 8

What is the main energy source for skeletal muscle contraction during peak activity?

Accepted Answer

Anaerobic glycolysis

Question 9

Which type of skeletal muscle fiber is most resistant to fatigue and why?

Accepted Answer

Slow fibers, due to high myoglobin and mitochondria content

Question 10

A muscle fiber is stimulated repeatedly at a frequency that does not allow complete relaxation between stimuli. What is this phenomenon called?

Accepted Answer

Wave summation

Question 11

Which of the following is TRUE regarding cardiac muscle cells?

Accepted Answer

They have intercalated discs and are striated

Question 12

Which process is responsible for the removal and recycling of lactate produced during intense muscle activity?

Accepted Answer

Cori cycle

Question 13

Which of the following best explains why smooth muscle can contract even when greatly stretched?

Accepted Answer

It exhibits plasticity due to the lack of sarcomeres

Question 14

Which hormone does NOT directly increase muscle metabolism?

Accepted Answer

Insulin

Question 15

A muscle is attached to a 2 kg weight and develops enough tension to lift it, shortening as it contracts. What type of contraction is this?

Accepted Answer

Isotonic concentric contraction

Question 16

Which of the following is the correct sequence of events in excitation-contraction coupling?

Accepted Answer

Action potential → ACh release → Ca$$^{2+}$$ release → Cross-bridge formation

Question 17

Which of the following best describes the role of titin in the sarcomere?

Accepted Answer

It stabilizes thick filaments and restores resting length

Question 18

Which of the following would most likely result in muscle atrophy?

Accepted Answer

Prolonged inactivity

Question 19

Which of the following is a characteristic unique to multiunit smooth muscle cells?

Accepted Answer

They are innervated in motor units

Question 20

A muscle fiber is producing maximum tension with no relaxation phase between stimuli. What is this state called?

Accepted Answer

Complete tetanus

Muscle Tissue: Structure, Function, and Contraction Mechanisms

Study Guide - Practice Questions