$$\text{ADP} + \text{Creatine Phosphate} \xrightarrow{\text{Creatine Kinase}} \text{ATP} + \text{Creatine}$$

$$\text{ATP} \xrightarrow{\text{ATPase}} \text{ADP} + \text{P}$$

Question 1

Which connective tissue layer surrounds individual muscle fibers and contains capillaries and nerves?

Accepted Answer

Endomysium

Question 2

During muscle contraction, which event directly triggers the release of calcium ions from the sarcoplasmic reticulum?

Accepted Answer

Action potential traveling down the T-tubules

Question 3

Which of the following best describes the function of the triad in skeletal muscle fibers?

Accepted Answer

Links electrical signals to calcium release for contraction

Question 4

What is the primary function of the sarcolemma in muscle fibers?

Accepted Answer

Conducts action potentials that initiate contraction

Question 5

Which equation represents the phosphorylation of ADP by creatine phosphate during muscle contraction?

Accepted Answer

$$	ext{ADP} + 	ext{Creatine Phosphate} \xrightarrow{	ext{Creatine Kinase}} 	ext{ATP} + 	ext{Creatine}$$

Question 6

Which protein blocks the myosin-binding sites on actin in a resting muscle?

Accepted Answer

Tropomyosin

Question 7

A patient with muscle fatigue is found to have a buildup of lactic acid. Which pathway is primarily responsible for this?

Accepted Answer

Anaerobic glycolysis in the cytosol

Question 8

Which of the following changes occur in the sarcomere during muscle contraction?

Accepted Answer

I band shortens

Question 9

What is the correct sequence of events leading to muscle contraction after an action potential arrives at the neuromuscular junction?

Accepted Answer

ACh release → Na⁺ influx → Action potential in sarcolemma → Ca²⁺ release → Cross-bridge formation

Question 10

Which muscle fiber type is best suited for endurance activities such as marathon running?

Accepted Answer

Slow oxidative fibers (Type I)

Question 11

Which structural protein provides passive elasticity and stabilizes thick filaments within the sarcomere?

Accepted Answer

Titin

Question 12

In cardiac muscle tissue, what is the function of intercalated discs?

Accepted Answer

Join cell membranes, conduct action potentials, and maintain structure

Question 13

Which of the following is TRUE regarding the all-or-none principle in muscle fibers?

Accepted Answer

A muscle fiber is either fully contracted or fully relaxed

Question 14

Which phase of a muscle twitch involves the release of Ca²⁺ from the sarcoplasmic reticulum but no tension production?

Accepted Answer

Latent period

Question 15

Which equation best represents the hydrolysis of ATP during the cross-bridge cycle?

Accepted Answer

$$	ext{ATP} \xrightarrow{	ext{ATPase}} 	ext{ADP} + 	ext{P}$$

Question 16

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

Accepted Answer

Spindle-shaped cells with a single nucleus

Question 17

What is the main physiological role of the terminal cisternae in skeletal muscle fibers?

Accepted Answer

Store and release Ca²⁺ to initiate contraction

Question 18

Which event marks the end of muscle contraction and the beginning of relaxation?

Accepted Answer

Ca²⁺ is pumped back into the sarcoplasmic reticulum by SERCA pumps

Question 19

Which of the following best explains why rigor mortis occurs after death?

Accepted Answer

ATP is no longer produced, preventing myosin detachment from actin

Question 20

Which muscle contraction type involves tension production without a change in muscle length?

Accepted Answer

Isometric contraction

Muscle Tissue: Structure, Function, and Contraction Mechanisms

Study Guide - Practice Questions