Q: Which equation represents the restoration of ionic conditions after muscle repolarization?

$$3\mathrm{Na}^+_{\text{out}} + 2\mathrm{K}^+_{\text{in}} \xrightarrow{\text{Na^+-K^+ pump}} 3\mathrm{Na}^+_{\text{in}} + 2\mathrm{K}^+_{\text{out}}$$

Question 1

Which of the following muscle types is under voluntary control and contains multiple nuclei per cell?

Accepted Answer

Skeletal muscle

Question 2

A patient presents with muscle tissue that is striated, involuntary, and uninucleated. Which muscle type is most likely affected?

Accepted Answer

Cardiac muscle

Question 3

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

Accepted Answer

Elasticity

Question 4

During a marathon, which muscle function is most critical for maintaining upright posture over long periods?

Accepted Answer

Maintaining posture and body position

Question 5

Which connective tissue sheath surrounds individual muscle fibers in skeletal muscle?

Accepted Answer

Endomysium

Question 6

A muscle attaches to bone via a ropelike tendon that extends beyond the muscle. This is an example of which type of attachment?

Accepted Answer

Indirect attachment

Question 7

Which organelle in skeletal muscle fibers is responsible for storing glycogen?

Accepted Answer

Glycosome

Question 8

If a muscle fiber has many mitochondria and myoglobin, what is its primary advantage?

Accepted Answer

Enhanced oxygen storage and aerobic ATP production

Question 9

Which of the following equations correctly represents the direct phosphorylation of ADP by creatine phosphate (CP) in muscle metabolism?

Accepted Answer

$$\mathrm{CP} + \mathrm{ADP} \rightarrow \mathrm{Creatine} + \mathrm{ATP}$$

Question 10

A muscle fiber is stimulated but does not change length, even though tension increases. What type of contraction is this?

Accepted Answer

Isometric contraction

Question 11

Which phase of a muscle twitch corresponds to the time when Ca$$^{2+} is re-$$entering the sarcoplasmic reticulum and muscle tension declines?

Accepted Answer

Period of relaxation

Question 12

During high-intensity exercise, oxygen delivery to muscles is impaired and pyruvic acid is converted to lactic acid. Which metabolic pathway is primarily responsible for ATP production under these conditions?

Accepted Answer

Anaerobic glycolysis

Question 13

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

Accepted Answer

It stores and releases Ca$$^{2+}$$ ions

Question 14

A muscle fiber is unable to contract further due to a lack of ATP and accumulation of lactic acid. What is this condition called?

Accepted Answer

Muscle fatigue

Question 15

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

Accepted Answer

Hormone secretion

Question 16

Which structure connects groups of muscle fibers into fascicles in skeletal muscle?

Accepted Answer

Perimysium

Question 17

Which of the following best explains why skeletal muscle fibers are multinucleated?

Accepted Answer

They fuse from multiple myoblasts during development

Question 18

Which muscle tissue type is most likely to be found in the walls of blood vessels, and what is its control mechanism?

Accepted Answer

Smooth muscle; involuntary control

Question 19

Which of the following is a correct sequence of events at the neuromuscular junction leading to muscle contraction?

Accepted Answer

Release of acetylcholine, binding to sarcolemma receptors, generation of action potential

Question 20

Which equation represents the restoration of ionic conditions after muscle repolarization?

Accepted Answer

$$3\mathrm{Na}^+_{	ext{out}} + 2\mathrm{K}^+_{	ext{in}} \xrightarrow{	ext{Na^+-K^+ pump}} 3\mathrm{Na}^+_{	ext{in}} + 2\mathrm{K}^+_{	ext{out}}$$

Chapter 9: Muscles – Structure and Function in Anatomy & Physiology

Study Guide - Practice Questions

Study Guide - Flashcards