Question 1

Which connective tissue layer surrounds individual muscle fibers within a skeletal muscle?

Accepted Answer

Endomysium

Question 2

During the contraction of a skeletal muscle fiber, which of the following occurs according to the sliding-filament theory?

Accepted Answer

The Z lines move closer together

Question 3

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

Accepted Answer

Troponin

Question 4

A patient is unable to relax their muscles after death, resulting in rigor mortis. What is the primary cause of this phenomenon?

Accepted Answer

Lack of ATP and accumulation of Ca$$^{2+} in $$the cytosol

Question 5

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

Accepted Answer

Stores and releases calcium ions

Question 6

Which type of muscle contraction occurs when muscle tension exceeds the load and the muscle shortens?

Accepted Answer

Isotonic concentric contraction

Question 7

What is the role of acetylcholinesterase (AChE) at the neuromuscular junction?

Accepted Answer

It breaks down acetylcholine, ending muscle stimulation

Question 8

Which of the following is true regarding fast muscle fibers?

Accepted Answer

They contract quickly and fatigue rapidly

Question 9

A muscle fiber is stimulated repeatedly before it can relax completely, resulting in a sustained, smooth contraction. What is this phenomenon called?

Accepted Answer

Complete tetanus

Question 10

Which of the following best explains why cardiac muscle cannot undergo tetanic contractions?

Accepted Answer

Cardiac muscle cells have long refractory periods

Question 11

Which of the following is a unique property of smooth muscle compared to skeletal muscle?

Accepted Answer

Ability to contract over a wide range of lengths (plasticity)

Question 12

Which of the following best describes the function of intercalated discs in cardiac muscle?

Accepted Answer

They allow ions to move between cells, synchronizing contraction

Question 13

Which metabolic pathway is the primary source of ATP for skeletal muscles at rest?

Accepted Answer

Aerobic metabolism of fatty acids

Question 14

A muscle is contracting but does not change length because the tension produced does not exceed the load. What type of contraction is this?

Accepted Answer

Isometric

Question 15

Which of the following is a function of skeletal muscle tissue?

Accepted Answer

Moving the body by pulling on bones

Question 16

Which of the following best describes the process of muscle hypertrophy?

Accepted Answer

Increase in diameter, myofibrils, mitochondria, and glycogen reserves

Question 17

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

Accepted Answer

Action potential travels down T tubules → Ca$$^{2+}$$ released from SR → Troponin binds Ca$$^{2+}$$ → Active sites exposed

Question 18

Which of the following is a characteristic of slow muscle fibers?

Accepted Answer

High myoglobin content and many mitochondria

Question 19

Which of the following best describes the role of creatine phosphate (CP) in muscle contraction?

Accepted Answer

It stores energy that is used to convert ADP to ATP

Question 20

Which of the following is true regarding the length-tension relationship in skeletal muscle?

Accepted Answer

Maximum tension is produced when the maximum number of cross-bridges can form

Muscle Tissue: Structure, Organization, and Function

Study Guide - Practice Questions