Question 1

Which of the following factors would most directly increase the force of skeletal muscle contraction during a weightlifting exercise?

Accepted Answer

Increasing the frequency of stimulation to the muscle fibers

Question 2

A marathon runner is most likely to have a higher proportion of which type of muscle fiber in their leg muscles?

Accepted Answer

Slow oxidative fibers

Question 3

If a muscle fiber is stretched to 130% of its normal resting length, what happens to its ability to generate force?

Accepted Answer

It generates less force because thin and thick filaments do not overlap optimally

Question 4

Which metabolic pathway is primarily used by fast glycolytic muscle fibers during a short, intense activity such as hitting a baseball?

Accepted Answer

Anaerobic glycolysis

Question 5

During resistance training, which cellular change is most responsible for increased muscle strength?

Accepted Answer

Hypertrophy, or increase in muscle fiber size

Question 6

Which of the following best explains why smooth muscle can maintain contraction for prolonged periods with minimal energy expenditure?

Accepted Answer

Latch state, where actin and myosin remain attached

Question 7

A patient with intermittent claudication experiences muscle pain during walking due to blocked arteries. Which muscle property is most affected?

Accepted Answer

Resistance to fatigue

Question 8

Which of the following is TRUE regarding the organization of smooth muscle in the walls of hollow organs?

Accepted Answer

It is arranged in two layers: longitudinal and circular

Question 9

Which protein binds calcium ions to initiate contraction in smooth muscle?

Accepted Answer

Calmodulin

Question 10

Which equation best represents the relationship between muscle force ($$F$$), cross-sectional area ($$A$$), and muscle fiber tension ($$T$$)?

Accepted Answer

$$F = T 	imes A$$

Question 11

Which of the following is a key difference between single-unit (unitary) and multiunit smooth muscle?

Accepted Answer

Single-unit smooth muscle cells are electrically coupled by gap junctions

Question 12

Which neurotransmitter can have either a stimulatory or inhibitory effect on smooth muscle, depending on the receptor type present?

Accepted Answer

Acetylcholine

Question 13

What is the primary reason that skeletal muscle fibers are multinucleated?

Accepted Answer

They form by fusion of multiple embryonic myoblasts

Question 14

Which of the following best describes the effect of endurance (aerobic) exercise on skeletal muscle?

Accepted Answer

Increased number of mitochondria and greater resistance to fatigue

Question 15

Which muscle fiber type is best suited for activities such as sprinting or walking?

Accepted Answer

Fast oxidative fibers

Question 16

Which of the following statements about muscle contraction is correct?

Accepted Answer

The number of cross bridges formed between actin and myosin determines the force of contraction

Question 17

Which process is required for smooth muscle relaxation after contraction?

Accepted Answer

Active transport of Ca$$^{2+}$$ into the SR and extracellular space

Question 18

Which of the following is a function of synergist muscles during movement?

Accepted Answer

They add extra force to the same movement as the prime mover

Question 19

Which equation best describes the relationship between ATP hydrolysis rate ($$r$$), contraction velocity ($$v$$), and myosin ATPase activity ($$a) in $$muscle fibers?

Accepted Answer

$$v = r 	imes a$$

Question 20

Which of the following changes occurs in skeletal muscle as a result of aging?

Accepted Answer

Connective tissue increases and muscle fibers decrease, leading to sarcopenia

Muscle Contraction and Muscle Fiber Types: Structure, Function, and Physiology

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