$$MA = \frac{\text{effort arm}}{\text{load arm}}$$

Question 1

Which of the following adaptations is most likely to occur in skeletal muscle after several weeks of endurance exercise such as jogging or swimming?

Accepted Answer

Increase in mitochondria, capillaries, and resistance to fatigue

Question 2

A patient is immobilized in a cast for two weeks. Which process is most responsible for the observed decrease in muscle mass?

Accepted Answer

Atrophy

Question 3

Which statement best describes the arrangement of smooth muscle layers in most hollow organs?

Accepted Answer

Two layers: longitudinal and circular, oriented at right angles to each other

Question 4

What is the primary function of gap junctions in smooth muscle tissue?

Accepted Answer

To allow rapid transmission of action potentials and ions between adjacent cells

Question 5

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

Accepted Answer

Smooth muscle maintains a moderate degree of contraction constantly without fatiguing

Question 6

During muscle contraction, which factor will most directly increase the force generated by a skeletal muscle?

Accepted Answer

Increasing the number of muscle fibers stimulated (recruitment)

Question 7

A muscle is stretched so that its sarcomeres are at 80–120% of their normal resting length. What effect does this have on force generation?

Accepted Answer

Force generation is maximized

Question 8

Which term describes the attachment point of a skeletal muscle that does NOT move during contraction?

Accepted Answer

Origin

Question 9

Which muscle group is primarily responsible for jaw closure during mastication?

Accepted Answer

Temporalis and masseter

Question 10

Which muscles are involved in enlarging the rib cage during inspiration?

Accepted Answer

Diaphragm and external intercostals

Question 11

A patient is unable to flex their forearm at the elbow. Which muscle is most likely impaired?

Accepted Answer

Biceps brachii

Question 12

Which muscle is the prime mover for thigh flexion at the hip joint?

Accepted Answer

Iliopsoas

Question 13

Which group of muscles is responsible for extension of the thigh and flexion of the knee?

Accepted Answer

Hamstrings

Question 14

Which muscle is attached to the calcaneus via the Achilles tendon and is involved in plantar flexion of the ankle?

Accepted Answer

Gastrocnemius

Question 15

Which of the following equations best represents the mechanical advantage of a lever system in the human body?

Accepted Answer

$$MA = \frac{	ext{effort arm}}{	ext{load arm}}$$

Question 16

Which muscle acts as a synergist to stabilize the scapula during arm movements?

Accepted Answer

Trapezius

Question 17

Which neurotransmitter is most commonly released at the diffuse junctions of smooth muscle tissue?

Accepted Answer

Acetylcholine

Question 18

A muscle that opposes the action of a prime mover is called a(n):

Accepted Answer

Antagonist

Question 19

Which muscle is primarily responsible for dorsiflexion of the ankle?

Accepted Answer

Tibialis anterior

Question 20

Which of the following best describes the effect of neurotransmitter binding on smooth muscle contraction?

Accepted Answer

It can be stimulatory in one organ and inhibitory in another

Chapter 10: The Muscular System – Structure, Function, and Movement

Guida di studio - Domande di pratica