Question 1

Which of the following is NOT a primary function of the muscular system?

Accepted Answer

Hormone production

Question 2

During a biceps curl, which movement occurs at the elbow joint as the weight is lifted upward?

Accepted Answer

Flexion

Question 3

Which layer of connective tissue surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 4

A person is performing a jumping jack. What movement is occurring at the shoulder as the arms move away from the body?

Accepted Answer

Abduction

Question 5

Which structure carries the action potential deep into the muscle fiber to trigger contraction?

Accepted Answer

Transverse tubules (T-tubules)

Question 6

What is the role of calcium ions ($$Ca^{2+}) in $$muscle contraction?

Accepted Answer

They bind to troponin, causing tropomyosin to move and expose myosin binding sites on actin.

Question 7

Which protein prevents overstretching of the sarcomere and connects the ends of myosin thick filaments to the actin backbone?

Accepted Answer

Titin

Question 8

If a person is unable to maintain posture due to muscle weakness, which function of the muscular system is most directly affected?

Accepted Answer

Posture

Question 9

Which of the following best describes the sliding filament theory of muscle contraction?

Accepted Answer

Thin filaments slide past thick filaments, shortening the sarcomere.

Question 10

A patient presents with muscle fatigue after prolonged exercise. Which of the following is a plausible physiological explanation?

Accepted Answer

Leaky calcium channels in the sarcoplasmic reticulum

Question 11

Which connective tissue layer contains capillary beds and satellite cells?

Accepted Answer

Endomysium

Question 12

What is the correct sequence of events for muscle contraction initiation?

Accepted Answer

Action potential arrives at neuromuscular junction → Calcium released from sarcoplasmic reticulum → Myosin binds to actin

Question 13

Which of the following movements describes turning the palm upward?

Accepted Answer

Supination

Question 14

Which metabolic pathway provides indefinite energy for muscle contraction, limited only by oxygen supply?

Accepted Answer

Aerobic metabolism

Question 15

A muscle fiber is stimulated by a motor neuron at the neuromuscular junction. What is the name of the specialized region on the muscle side where this occurs?

Accepted Answer

Motor end plate

Question 16

Which of the following best explains why muscle fibers are multinucleated?

Accepted Answer

They fuse from multiple myoblasts during development.

Question 17

Which structure is responsible for storing and releasing calcium ions during muscle contraction?

Accepted Answer

Sarcoplasmic reticulum

Question 18

Which of the following is true about motor units?

Accepted Answer

A motor unit consists of a single neuron and all the muscle fibers it innervates.

Question 19

Which of the following movements is described as moving a limb toward the midline of the body?

Accepted Answer

Adduction

Question 20

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

Accepted Answer

ATP is required for myosin head detachment from actin after the power stroke.

Muscular System: Structure, Function, and Axial Musculature

Guida di studio - Domande di pratica

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