Question 1

Which of the following muscle types is responsible for moving food through the digestive tract?

Accepted Answer

Smooth muscle

Question 2

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

Accepted Answer

To store and release calcium ions ($$\mathrm{Ca$$^{2+}$$}) $$during contraction

Question 3

Which structure in a muscle fiber is responsible for transmitting the action potential deep into the cell?

Accepted Answer

T tubule

Question 4

During the sliding filament model of contraction, which event occurs as myosin heads bind to actin?

Accepted Answer

Cross bridges form and pull actin filaments toward the center of the sarcomere

Question 5

Which of the following best describes the role of acetylcholine (ACh) at the neuromuscular junction?

Accepted Answer

ACh binds to receptors on the sarcolemma, causing sodium channels to open and initiate an action potential

Question 6

Which of the following is NOT a characteristic shared by all muscle tissue?

Accepted Answer

Secretion

Question 7

A patient with Duchenne muscular dystrophy (DMD) is likely to have a defect in which protein?

Accepted Answer

Dystrophin

Question 8

Which of the following best explains why skeletal muscle fibers fatigue after prolonged activity?

Accepted Answer

Depletion of ATP and accumulation of metabolic byproducts

Question 9

Which of the following events occurs FIRST during the generation of an action potential at the neuromuscular junction?

Accepted Answer

Release of acetylcholine from synaptic vesicles

Question 10

Which of the following correctly matches the muscle type with its control mechanism?

Accepted Answer

Smooth muscle: involuntary

Question 11

Which protein blocks myosin binding sites on actin in a relaxed muscle fiber?

Accepted Answer

Tropomyosin

Question 12

What is the function of myoglobin in muscle cells?

Accepted Answer

Binds oxygen for use during aerobic respiration

Question 13

Which of the following structures is the functional unit of a skeletal muscle fiber?

Accepted Answer

Sarcomere

Question 14

During muscle contraction, which band in the sarcomere shortens?

Accepted Answer

I band

Question 15

Which of the following is a correct sequence of events for muscle fiber contraction?

Accepted Answer

Neurotransmitter release, action potential generation, excitation-contraction coupling, cross bridge cycling

Question 16

Which of the following is true regarding the attachment of muscles to bones?

Accepted Answer

The origin is attached to the immovable bone, and the insertion to the movable bone

Question 17

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

Accepted Answer

Pumping blood throughout the body

Question 18

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

Accepted Answer

ATP is required for myosin heads to detach from actin after the power stroke

Question 19

Which of the following is a correct description of the Z disc in a sarcomere?

Accepted Answer

It is a coin-shaped sheet of proteins that anchors thin filaments

Question 20

Which of the following is a consequence of defective dystrophin protein in muscle cells?

Accepted Answer

Disrupted attachment of actin filaments to the extracellular matrix

Muscle Tissue: Structure, Function, and Physiology

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