Question 1

Which of the following best describes the role of the sarcoplasmic reticulum in skeletal muscle contraction?

Accepted Answer

It stores and releases calcium ions necessary for muscle contraction.

Question 2

During the process of muscle contraction, which event occurs immediately after acetylcholine binds to receptors on the sarcolemma?

Accepted Answer

The membrane becomes permeable to sodium ions, leading to depolarization.

Question 3

Which connective tissue layer surrounds individual muscle fibers?

Accepted Answer

Endomysium

Question 4

A motor unit consists of:

Accepted Answer

A motor neuron and all the muscle fibers it innervates.

Question 5

Which region of the sarcomere contains only actin filaments?

Accepted Answer

I band

Question 6

What is the correct order of events in the excitation-contraction coupling of skeletal muscle?

Accepted Answer

Action potential arrives at axon terminal → Acetylcholine released → Sarcolemma depolarizes → T-tubules transmit signal → Calcium released from sarcoplasmic reticulum

Question 7

Which muscle is the prime mover (agonist) for elbow flexion?

Accepted Answer

Biceps brachii

Question 8

A muscle named 'sternocleidomastoid' indicates which of the following?

Accepted Answer

Its origins are on the sternum and clavicle, and its insertion is on the mastoid process.

Question 9

Which of the following best explains the 'all-or-none' principle of muscle contraction?

Accepted Answer

A muscle fiber either contracts fully or not at all in response to a threshold stimulus.

Question 10

Which phase of a muscle twitch corresponds to the time when calcium ions are being released and cross-bridge cycling begins?

Accepted Answer

Contraction phase

Question 11

If a muscle is stimulated at a frequency that prevents any relaxation between contractions, what is this phenomenon called?

Accepted Answer

Fused (complete) tetanus

Question 12

Which equation correctly represents the calculation of power in muscle physiology?

Accepted Answer

$$Power = \frac{Work}{Time}$$

Question 13

A patient is unable to smile or frown due to paralysis of facial muscles. Which anatomical feature explains why facial muscles can move the skin rather than bones?

Accepted Answer

Facial muscles insert into the skin, not just bone.

Question 14

Which of the following is a synergist muscle during jaw closure?

Accepted Answer

Temporalis

Question 15

Which type of muscle contraction occurs when muscle length does not change but tension increases, such as holding a weight steady?

Accepted Answer

Isometric contraction

Question 16

Which of the following best describes the function of the T-tubules in skeletal muscle fibers?

Accepted Answer

They transmit the action potential deep into the muscle fiber.

Question 17

A muscle named 'adductor longus' is likely to:

Accepted Answer

Move a limb toward the midline and be relatively long in length.

Question 18

Which of the following is true regarding the refractory periods in muscle contraction?

Accepted Answer

During the absolute refractory period, no new action potential can be generated.

Question 19

Which of the following best explains muscle fatigue during prolonged activity?

Accepted Answer

It results from depletion of ATP and accumulation of lactic acid.

Question 20

Which equation best represents the relationship between force, work, and distance in muscle physiology?

Accepted Answer

$$Work = Force 	imes Distance$$

Muscle Structure and Function: Anatomy & Physiology Lab 7 Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard