$$\text{Glucose} + 6\,O_2$ \rightarrow 6\,CO_2$ + 6\,H_2O + 34\,ATP$$

Question 1

Which connective tissue layer surrounds individual skeletal muscle fibers and contains capillaries, nerve fibers, and satellite cells?

Accepted Answer

Endomysium

Question 2

During muscle contraction, which event directly exposes the active sites on F actin, allowing myosin heads to bind?

Accepted Answer

Release of Ca$$^{2+}$$ from the sarcoplasmic reticulum

Question 3

A patient experiences muscle fatigue after intense exercise. Which of the following is NOT a direct result of muscle fatigue?

Accepted Answer

Increase in muscle tone and power

Question 4

Which of the following best describes the sliding filament theory of muscle contraction?

Accepted Answer

Thin filaments slide toward the M line, shortening the sarcomere

Question 5

Which equation correctly represents the net ATP yield from aerobic metabolism of one glucose molecule in skeletal muscle?

Accepted Answer

$$	ext{Glucose} + 6\,O_2$ ightarrow 6\,CO_2$ + 6\,H_2O + 34\,ATP$$

Question 6

Which muscle fiber type is most abundant in muscles used for endurance activities, such as marathon running?

Accepted Answer

Slow fibers

Question 7

A muscle is contracting but not changing length, even though tension is increasing. What type of contraction is this?

Accepted Answer

Isometric contraction

Question 8

Which structure is responsible for transmitting action potentials deep into the muscle fiber, ensuring simultaneous contraction?

Accepted Answer

Transverse tubules (T tubules)

Question 9

In cardiac muscle, intercalated discs serve which primary function?

Accepted Answer

Conducting action potentials and linking cells mechanically, chemically, and electrically

Question 10

Which process occurs during the recovery period after intense muscle activity, helping to restore muscle glycogen reserves?

Accepted Answer

The Cori cycle converts lactic acid to pyruvic acid in the liver, then to glucose

Question 11

Which of the following is TRUE regarding smooth muscle contraction?

Accepted Answer

Ca$$^{2+}$$ binds to calmodulin, activating myosin light chain kinase

Question 12

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

Accepted Answer

Ion pumps cease to function, Ca$$^{2+}$$ builds up in the sarcoplasm, and muscles remain contracted

Question 13

Which of the following is a characteristic unique to cardiac muscle cells (cardiocytes) compared to skeletal muscle fibers?

Accepted Answer

Presence of intercalated discs

Question 14

A muscle fiber is unable to contract because ATP is unavailable. Which step of the contraction cycle is directly affected?

Accepted Answer

Reactivation of myosin heads

Question 15

Which of the following statements about muscle relaxation is correct?

Accepted Answer

Relaxation occurs when Ca$$^{2+}$$ concentrations fall and tropomyosin covers active sites

Question 16

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

Accepted Answer

Conducting action potentials between cells via intercalated discs

Question 17

Which of the following best describes the relationship between resistance and speed of muscle contraction?

Accepted Answer

As resistance increases, speed of contraction decreases

Question 18

Which of the following is TRUE regarding the energy sources for muscle contraction during peak exertion?

Accepted Answer

Muscles rely primarily on anaerobic glycolysis, producing lactic acid

Question 19

Which of the following is a structural feature of smooth muscle cells that allows them to transmit contractions from cell to cell?

Accepted Answer

Dense bodies

Question 20

Which of the following best describes muscle hypertrophy?

Accepted Answer

Increase in muscle fiber diameter, number of myofibrils, mitochondria, and glycogen reserves

A&P: lecture exam 3 pt 1

Study Guide - Practice Questions