Question 1

Which of the following best describes the role of the endomysium in skeletal muscle tissue?

Accepted Answer

It surrounds individual muscle fibers, providing insulation and support.

Question 2

A patient suffers a deep laceration that severs the tendon connecting the biceps brachii to the radius. Which of the following best describes the consequence of this injury?

Accepted Answer

The muscle can contract, but movement at the elbow joint is severely impaired because the force cannot be transmitted to the bone.

Question 3

Which of the following is a key advantage of skeletal muscle fibers being multinucleated?

Accepted Answer

They can synthesize large amounts of proteins needed for muscle contraction and repair.

Question 4

Which two proteins are primarily responsible for the striated appearance of skeletal muscle fibers?

Accepted Answer

Actin and myosin

Question 5

During the process of muscle contraction, which ion must bind to troponin to initiate the exposure of active sites on G-actin?

Accepted Answer

Calcium ions ($$\mathrm{Ca$$^{2+}$$})$$

Question 6

A muscle fiber is at rest with a membrane potential of $$-85\ \mathrm{mV}. $$What event occurs when voltage-gated sodium channels open?

Accepted Answer

Sodium ions enter the cell, causing depolarization.

Question 7

Which of the following best describes the function of the sodium-potassium pump during the refractory period of a muscle fiber?

Accepted Answer

It restores ion gradients by moving $$3\ \mathrm{Na^+}$$ out and $$2\ \mathrm{K^+} in $$per ATP hydrolyzed.

Question 8

Which of the following events occurs immediately after acetylcholine (ACh) is released into the synaptic cleft at the neuromuscular junction?

Accepted Answer

ACh binds to chemically gated sodium channels on the motor end plate, causing them to open.

Question 9

Which of the following best explains the phenomenon of wave summation in muscle contraction?

Accepted Answer

Successive stimuli arrive before the muscle has completely relaxed, resulting in increased tension.

Question 10

A muscle is stimulated repeatedly at a frequency that does not allow complete relaxation between stimuli, resulting in a sustained but fluctuating contraction. What is this condition called?

Accepted Answer

Incomplete tetanus

Question 11

Which of the following best describes the difference between isotonic and isometric muscle contractions?

Accepted Answer

Isotonic contractions change muscle length, while isometric contractions do not.

Question 12

Which energy source is used to 'cock' the myosin head during the contraction cycle?

Accepted Answer

ATP

Question 13

If oxygen is not available during intense exercise, what is pyruvate converted to in skeletal muscle fibers?

Accepted Answer

Lactic acid

Question 14

Which type of muscle fiber is most likely to fatigue quickly due to relatively few mitochondria?

Accepted Answer

Fast glycolytic (fast-twitch) fibers

Question 15

Which of the following is a characteristic unique to cardiac muscle tissue compared to skeletal muscle?

Accepted Answer

Presence of intercalated discs that allow synchronized contraction

Question 16

Which protein does calcium bind to in smooth muscle to initiate contraction?

Accepted Answer

Calmodulin

Question 17

A patient is diagnosed with tetanus (lockjaw) after a puncture wound. Which type of molecule released by Clostridium is responsible for this condition?

Accepted Answer

A neurotoxin

Question 18

Which enzyme is responsible for breaking down acetylcholine (ACh) in the synaptic cleft?

Accepted Answer

Acetylcholinesterase

Question 19

Which of the following best describes the function of creatine phosphate in skeletal muscle?

Accepted Answer

It donates a phosphate group to ADP to rapidly regenerate ATP during short bursts of activity.

Question 20

Which of the following best explains why smooth muscle contractions are considered involuntary?

Accepted Answer

They are not under conscious control and are regulated by the autonomic nervous system.

Chapter 10: Muscle Tissue Study Guide – Step-by-Step Guidance

Study Guide - Practice Questions

Study Guide - Flashcards