Q: Which equation best represents the generation of an action potential in a muscle fiber?

$$ \text{Depolarization}: \text{Na}^+ \text{influx} \rightarrow \text{Threshold} \rightarrow \text{Action Potential} $$

Q: Which of the following equations represents the regeneration of ATP via creatine phosphate during muscle contraction?

$$ \text{Creatine phosphate} + \text{ADP} \rightarrow \text{Creatine} + \text{ATP} $$

Question 1

Which of the following statements best distinguishes cardiac muscle from skeletal and smooth muscle?

Accepted Answer

Cardiac muscle fibers are striated and involuntary.

Question 2

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

Accepted Answer

Storing calcium

Question 3

A skeletal muscle is composed of several structures. Which of the following correctly matches the structure with its function?

Accepted Answer

Connective tissues: provide structural support and transmit force

Question 4

Which component of a skeletal muscle fiber stores calcium ions necessary for muscle contraction?

Accepted Answer

Sarcoplasmic reticulum

Question 5

According to the sliding filament model, which event directly causes the shortening of a muscle fiber?

Accepted Answer

Binding of myosin heads to actin and pulling the filaments

Question 6

During muscle contraction, which sequence correctly describes the events at the neuromuscular junction?

Accepted Answer

Acetylcholine is released, binds to receptors, sodium enters the cell, action potential is generated

Question 7

Which equation best represents the generation of an action potential in a muscle fiber?

Accepted Answer

$$ 	ext{Depolarization}: 	ext{Na}^+ 	ext{influx} ightarrow 	ext{Threshold} ightarrow 	ext{Action Potential} $$

Question 8

Excitation-contraction coupling involves several steps. Which of the following is the correct order?

Accepted Answer

Action potential travels along sarcolemma → T tubules → Sarcoplasmic reticulum releases Ca$$^{2+}$$ → Cross-bridge formation

Question 9

Which of the following best defines a motor unit?

Accepted Answer

A group of muscle fibers innervated by a single motor neuron

Question 10

Which scenario best illustrates an isometric contraction?

Accepted Answer

Holding a heavy box steady without moving it

Question 11

Which of the following equations represents the regeneration of ATP via creatine phosphate during muscle contraction?

Accepted Answer

$$ 	ext{Creatine phosphate} + 	ext{ADP} ightarrow 	ext{Creatine} + 	ext{ATP} $$

Question 12

Muscle fatigue can occur for several reasons. Which of the following is NOT a cause of muscle fatigue?

Accepted Answer

Increased calcium release from the sarcoplasmic reticulum

Question 13

Which type of skeletal muscle fiber is best suited for endurance activities such as marathon running?

Accepted Answer

Slow oxidative fibers

Question 14

In a biceps curl, which muscle acts as the prime mover?

Accepted Answer

Biceps brachii

Question 15

Which of the following is NOT a criterion used in naming muscles?

Accepted Answer

Amount of ATP produced

Question 16

A lever system in the body operates at a mechanical advantage when:

Accepted Answer

The effort is farther from the fulcrum than the load

Question 17

In the context of muscle movement, which equation best represents the relationship between effort, load, and fulcrum in a lever system?

Accepted Answer

$$ 	ext{Effort} 	imes 	ext{Effort Arm} = 	ext{Load} 	imes 	ext{Load Arm} $$

Question 18

Which statement best describes the origin and insertion of a muscle?

Accepted Answer

Origin is the immovable attachment; insertion is the movable attachment

Question 19

A patient presents with muscle weakness and rapid fatigue during exercise. Laboratory tests show elevated lactic acid levels. Which pathway is most likely being used for ATP regeneration?

Accepted Answer

Anaerobic glycolysis

Question 20

During a squat, the quadriceps contract to extend the knee while the hamstrings relax. Which term best describes the role of the hamstrings in this movement?

Accepted Answer

Antagonist

Anatomy & Physiology: Muscular System Study Guide

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