$$F \times d_F = R \times d_R$$

Question 1

Which of the following properties is shared by all three types of muscle tissue and is defined as the ability to respond to stimulation?

Accepted Answer

Excitability

Question 2

A patient is unable to maintain posture and body position due to a muscular disorder. Which type of muscle tissue is most likely affected?

Accepted Answer

Skeletal muscle

Question 3

During muscle contraction, which event occurs according to the sliding filament theory?

Accepted Answer

The H band and I band get smaller

Question 4

Which equation best represents the relationship between force, lever arm, and resistance in a first-class lever system in the body?

Accepted Answer

$$F 	imes d_F = R 	imes d_R$$

Question 5

Which muscle fiber type is most likely to be dominant in a marathon runner, and why?

Accepted Answer

Slow fibers, because they use aerobic metabolism and resist fatigue

Question 6

A muscle that stabilizes the origin of the agonist during movement is called a:

Accepted Answer

Fixator

Question 7

Which of the following best describes the role of calcium ions in skeletal muscle contraction?

Accepted Answer

Calcium ions bind to troponin, causing a conformational change that exposes active sites on actin

Question 8

Which organizational pattern of skeletal muscle fibers allows for the greatest range of motion but the least force production?

Accepted Answer

Parallel

Question 9

If a muscle extends from a broad aponeurosis to a narrow tendon, which is considered the origin and which is the insertion?

Accepted Answer

Aponeurosis = origin; Tendon = insertion

Question 10

Which of the following changes would you expect in skeletal muscle as a result of aging?

Accepted Answer

Decrease in muscle diameter and elasticity

Question 11

A muscle that produces extension at a joint is acting as which type of muscle relative to a muscle that produces flexion?

Accepted Answer

Antagonist

Question 12

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

Accepted Answer

Push blood through arteries and veins

Question 13

Which muscle fiber type contains the most mitochondria and is most resistant to fatigue?

Accepted Answer

Slow fibers

Question 14

Which of the following best describes muscle hypertrophy?

Accepted Answer

Increase in mitochondria, glycolytic enzymes, glycogen reserves, and myofibril size

Question 15

Which of the following is true regarding the arrangement of motor units in a skeletal muscle?

Accepted Answer

Some motor units are always contracting, producing muscle tone

Question 16

Which muscle fiber organization is best suited for producing the greatest force?

Accepted Answer

Multipennate

Question 17

Which of the following statements about the neuromuscular synapse is correct?

Accepted Answer

It is the site where a motor neuron communicates with a muscle fiber

Question 18

Which of the following is a characteristic of second-class levers in the body?

Accepted Answer

The force is magnified, and the resistance moves more slowly and covers a shorter distance

Question 19

Which of the following best explains why fast muscle fibers fatigue easily?

Accepted Answer

Their mitochondria are unable to meet the demand for ATP during rapid contraction

Question 20

Which of the following events marks the end of a muscle contraction?

Accepted Answer

Recapture of calcium ions by the sarcoplasmic reticulum and covering of active sites by the troponin-tropomyosin complex

The Muscular System—Skeletal Muscle Tissue and Organization

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