Question 1

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

Accepted Answer

Production of hormones

Question 2

Skeletal muscle fibers are described as multinucleated and striated. What is the primary reason for their multinucleation?

Accepted Answer

Fusion of embryonic myoblasts during development

Question 3

Which structural feature is unique to cardiac muscle tissue and allows for coordinated contraction?

Accepted Answer

Intercalated discs

Question 4

Smooth muscle cells are found in all the following locations EXCEPT:

Accepted Answer

The heart

Question 5

Which property of muscle cells allows them to return to their original length after being stretched?

Accepted Answer

Elasticity

Question 6

The sarcoplasmic reticulum (SR) in muscle cells is primarily responsible for:

Accepted Answer

Storing and releasing calcium ions

Question 7

Which protein forms the thick filaments in a myofibril?

Accepted Answer

Myosin

Question 8

What is the role of tropomyosin in muscle contraction?

Accepted Answer

It covers the active sites on actin, preventing myosin binding

Question 9

During the sliding-filament mechanism, which of the following statements is TRUE?

Accepted Answer

The thin filaments slide toward the M line, shortening the sarcomere

Question 10

A muscle fiber at rest has a membrane potential of approximately:

Accepted Answer

$$-90\ \mathrm{mV}$$

Question 11

Which ion is primarily responsible for depolarizing the sarcolemma during an action potential?

Accepted Answer

Sodium ($$\mathrm{Na}^+)$$

Question 12

The sodium-potassium pump ($$\mathrm{Na}^+/\mathrm{K}^+$$ ATPase) moves ions in which direction?

Accepted Answer

Three $$\mathrm{Na}^+$$ out, two $$\mathrm{K}^+ in$$

Question 13

At the neuromuscular junction, which neurotransmitter is released to stimulate muscle contraction?

Accepted Answer

Acetylcholine (ACh)

Question 14

Which enzyme rapidly degrades acetylcholine in the synaptic cleft?

Accepted Answer

Acetylcholinesterase (AChE)

Question 15

What is the immediate source of energy for muscle contraction after stored ATP is depleted?

Accepted Answer

Creatine phosphate

Question 16

Which process provides the most ATP for sustained muscle activity?

Accepted Answer

Oxidative (aerobic) catabolism

Question 17

A muscle twitch consists of which three phases?

Accepted Answer

Latent period, contraction period, relaxation period

Question 18

Which type of muscle fiber is best suited for endurance activities?

Accepted Answer

Type I (slow oxidative)

Question 19

Which type of muscle contraction occurs when the muscle length does not change?

Accepted Answer

Isometric contraction

Question 20

Delayed-onset muscle soreness (DOMS) is primarily caused by:

Accepted Answer

Minor structural damage from isotonic eccentric contractions

Muscle Tissue and Physiology: Structure, Types, and Functions

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