$$ATP \rightarrow ADP + P_i + \text{energy}$$

Question 1

Which of the following statements best describes the difference between skeletal, cardiac, and smooth muscle tissue?

Accepted Answer

Skeletal muscle is striated and voluntary, cardiac muscle is striated and involuntary, and smooth muscle is non-striated and involuntary.

Question 2

Which function of muscle tissue is primarily responsible for maintaining posture?

Accepted Answer

Maintenance of posture

Question 3

A muscle fiber is surrounded by which layer of connective tissue?

Accepted Answer

Endomysium

Question 4

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

Accepted Answer

ATP binds to myosin, causing the myosin head to detach from actin and re-cock for another cycle.

Question 5

During the sliding filament mechanism of contraction, which event occurs first?

Accepted Answer

Cross bridge attachment of myosin to actin

Question 6

Which protein blocks the myosin binding sites on actin in a relaxed muscle?

Accepted Answer

Tropomyosin

Question 7

What is the function of the sarcoplasmic reticulum in muscle fibers?

Accepted Answer

It stores and releases calcium ions necessary for muscle contraction.

Question 8

Which of the following best describes the structure of a sarcomere?

Accepted Answer

It is the region between two Z lines and contains thick and thin filaments.

Question 9

Which of the following equations correctly represents the hydrolysis of ATP during muscle contraction?

Accepted Answer

$$ATP ightarrow ADP + P_i + 	ext{energy}$$

Question 10

A motor unit consists of:

Accepted Answer

All the muscle fibers innervated by a single motor neuron.

Question 11

Which of the following is NOT a characteristic of muscle tissue?

Accepted Answer

Ossification

Question 12

Which event directly triggers the release of calcium from the sarcoplasmic reticulum during muscle contraction?

Accepted Answer

Action potential traveling down the T-tubules

Question 13

Which of the following best explains why skeletal muscle fibers appear striated?

Accepted Answer

The regular arrangement of thick and thin filaments into sarcomeres.

Question 14

Which of the following steps occurs LAST in the sequence of events leading to muscle contraction?

Accepted Answer

Hydrolysis of ATP to re-cock the myosin head

Question 15

Which of the following is a function of the perimysium?

Accepted Answer

It surrounds bundles of muscle fibers called fascicles.

Question 16

If a muscle fiber is unable to release calcium from the sarcoplasmic reticulum, which process will be directly affected?

Accepted Answer

Formation of cross bridges between actin and myosin

Question 17

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

Accepted Answer

It binds to receptors on the motor end plate, initiating an action potential in the muscle fiber.

Question 18

Which of the following is the correct sequence of events in the cross bridge cycle?

Accepted Answer

Cross bridge attachment, power stroke, cross bridge detachment, cocking of myosin head

Question 19

Which of the following best explains the importance of the neuromuscular junction?

Accepted Answer

It is the site where the motor neuron communicates with the muscle fiber to initiate contraction.

Muscle Tissue: Structure, Function, and Contraction Mechanisms

Guida di studio - Domande di pratica