Question 1

Which type of muscle tissue is characterized by being involuntary, having no striations, and being found in the walls of hollow organs?

Accepted Answer

Smooth muscle

Question 2

What is the primary function of the sarcoplasmic reticulum in skeletal muscle fibers?

Accepted Answer

Storing and releasing Ca$$^{2+}$$ ions

Question 3

During muscle contraction, which event occurs immediately after acetylcholine (Ach) binds to its receptors on the sarcolemma?

Accepted Answer

Sodium channels open, causing depolarization

Question 4

Which connective tissue wrapping surrounds an individual muscle fiber?

Accepted Answer

Endomysium

Question 5

A patient is unable to relax their muscles after contraction. Which protein is most likely malfunctioning?

Accepted Answer

Tropomyosin

Question 6

Which of the following best describes the role of ATP in the cross-bridge cycle of muscle contraction?

Accepted Answer

ATP binds to myosin, causing it to detach from actin

Question 7

Which structure in the sarcomere serves as the anchor for actin filaments at the ends of the sarcomere?

Accepted Answer

Z disc

Question 8

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

Accepted Answer

Tetanus

Question 9

Which equation correctly represents the conversion of creatine phosphate (CP) to ATP in muscle cells?

Accepted Answer

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

Question 10

Which of the following is TRUE regarding aerobic respiration in muscle cells?

Accepted Answer

It requires oxygen and produces carbon dioxide

Question 11

A patient with low extracellular potassium (K$$^+) $$levels is experiencing muscle weakness. What is the physiological explanation?

Accepted Answer

Low K$$^+$$ inhibits sodium-potassium pump, preventing repolarization

Question 12

Which of the following best describes the function of myoglobin in muscle cells?

Accepted Answer

Binds oxygen for use in aerobic metabolism

Question 13

Which event directly triggers the release of calcium ions from the sarcoplasmic reticulum during muscle contraction?

Accepted Answer

Depolarization of the T-tubules

Question 14

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

Accepted Answer

Cells are branched and connected by gap junctions

Question 15

Which process is responsible for the return of calcium ions to the sarcoplasmic reticulum during muscle relaxation?

Accepted Answer

Active transport by ATP-dependent pumps

Question 16

Which of the following best describes the role of troponin in muscle contraction?

Accepted Answer

Troponin binds Ca$$^{2+}$$, causing tropomyosin to move and expose actin binding sites

Question 17

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

Accepted Answer

Propelling blood through the heart

Question 18

Which type of muscle contraction occurs when the muscle lengthens while generating force, such as lowering a weight?

Accepted Answer

Eccentric contraction

Question 19

Which of the following best explains why muscle cells have a rich blood supply?

Accepted Answer

To deliver oxygen and nutrients and remove metabolic wastes

Question 20

Which of the following is TRUE regarding the neuromuscular junction?

Accepted Answer

It is the site where a motor neuron contacts a skeletal muscle fiber

Skeletal Muscle: Structure, Function, and Physiology

Guida di studio - Domande di pratica