Question 1

Which connective tissue layer directly surrounds an individual muscle fiber?

Accepted Answer

Endomysium

Question 2

What is the functional contractile unit of a skeletal muscle fiber?

Accepted Answer

Sarcomere

Question 3

Which of the following best describes the A band in a sarcomere?

Accepted Answer

Contains both actin and myosin filaments

Question 4

During muscle contraction, which structure shortens?

Accepted Answer

Sarcomere

Question 5

Which of the following is the correct order of muscle organization from largest to smallest?

Accepted Answer

Muscle, fascicle, muscle fiber, myofibril

Question 6

What is the role of the sarcoplasmic reticulum in skeletal muscle fibers?

Accepted Answer

It stores and releases calcium ions

Question 7

Which of the following best describes the neuromuscular junction?

Accepted Answer

The site where a motor neuron communicates with a muscle fiber

Question 8

A patient is unable to contract their skeletal muscles due to a lack of acetylcholine release. Which structure is most likely malfunctioning?

Accepted Answer

Axon terminal of the motor neuron

Question 9

Which of the following statements about the I band is correct?

Accepted Answer

It contains only thin filaments

Question 10

If a muscle is unable to relax after contraction, which structure is most likely failing to function properly?

Accepted Answer

Sarcoplasmic reticulum

Question 11

Which of the following best describes the function of the perimysium?

Accepted Answer

It surrounds bundles of muscle fibers (fascicles)

Question 12

Which of the following is true regarding the sarcolemma?

Accepted Answer

It is the plasma membrane of a muscle fiber

Question 13

A muscle biopsy reveals a disruption in the Z discs. Which process would be most directly affected?

Accepted Answer

Organization and alignment of sarcomeres

Question 14

Which of the following best describes the H zone in a sarcomere?

Accepted Answer

It contains only thick filaments

Question 15

During an isotonic contraction, which of the following occurs?

Accepted Answer

The muscle changes length and moves a load

Question 16

Which of the following is a correct description of the M line in a sarcomere?

Accepted Answer

It anchors thick filaments

Question 17

A patient presents with muscle weakness. A biopsy shows a defect in the sarcolemma. Which process is most likely impaired?

Accepted Answer

Transmission of action potentials along the muscle fiber

Question 18

Which of the following best describes the relationship between actin and myosin during muscle contraction?

Accepted Answer

Actin and myosin filaments slide past each other

Question 19

Which of the following equations best represents the relationship between force, cross-sectional area, and tension in a muscle fiber?

Accepted Answer

$$T = \frac{F}{A}$$

Question 20

A muscle fiber is unable to contract even though the sarcolemma is depolarized. Which structure is most likely malfunctioning?

Accepted Answer

Sarcoplasmic reticulum

Microscopic Anatomy and Organization of Skeletal Muscle

Study Guide - Practice Questions