Question 1

Which of the following best explains why cardiac muscle cells can contract in a coordinated, wave-like fashion without direct nerve stimulation?

Accepted Answer

They contain intercalated disks with gap junctions that allow depolarization to spread rapidly between cells.

Question 2

A patient has a disorder affecting the calmodulin pathway in their muscle cells. Which type of muscle function is most likely to be impaired?

Accepted Answer

Smooth muscle contraction

Question 3

Which of the following statements about skeletal muscle is correct?

Accepted Answer

Skeletal muscle fibers are striated, multinucleated, and attached to bones.

Question 4

During a marathon, a runner's skeletal muscles become fatigued. Which property of skeletal muscle explains this phenomenon?

Accepted Answer

Skeletal muscle is voluntary and can become fatigued with prolonged use.

Question 5

Which of the following best describes the role of the autonomic nervous system (ANS) in muscle contraction?

Accepted Answer

The ANS can override and modulate contraction in both cardiac and smooth muscle.

Question 6

A histological slide shows muscle fibers that are spindle-shaped, uninucleate, and lack striations. Where in the body is this tissue most likely found?

Accepted Answer

Lining the gastrointestinal tract

Question 7

Which of the following is a key difference between cardiac and skeletal muscle?

Accepted Answer

Cardiac muscle fibers are branched and connected by intercalated disks; skeletal muscle fibers are unbranched and multinucleated.

Question 8

Which ion is essential for the contraction of all muscle types, and what is its primary role?

Accepted Answer

Calcium ($Ca^{2+}$); triggers the interaction of contractile proteins

Question 9

A patient with a heart condition has impaired function of their intercalated disks. What is the most likely consequence?

Accepted Answer

Reduced ability of cardiac muscle cells to synchronize contraction

Question 10

Which muscle type is most likely to contract in response to stretch, such as when blood vessels rebound after being filled?

Accepted Answer

Smooth muscle

Question 11

A drug that blocks acetylcholine receptors at the neuromuscular junction would primarily affect which muscle type?

Accepted Answer

Skeletal muscle

Question 12

Which of the following best explains why smooth muscle does not appear striated under the microscope?

Accepted Answer

Smooth muscle fibers have contractile proteins arranged in a non-parallel, irregular pattern.

Question 13

A muscle biopsy reveals branched, striated fibers with a single central nucleus and intercalated disks. Which muscle type is this?

Accepted Answer

Cardiac muscle

Question 14

Which of the following is true regarding the fatigue resistance of muscle types?

Accepted Answer

Smooth and cardiac muscles are more resistant to fatigue than skeletal muscle.

Question 15

Which of the following best describes the mechanism of contraction in smooth muscle?

Accepted Answer

Contraction is initiated by the binding of calcium to calmodulin, activating myosin light-chain kinase.

Question 16

A person is able to consciously flex their arm at the elbow. Which muscle type is responsible for this movement, and what is the neurotransmitter involved?

Accepted Answer

Skeletal muscle; acetylcholine

Question 17

Which of the following is a feature unique to cardiac muscle among the three muscle types?

Accepted Answer

Presence of intercalated disks

Question 18

If a muscle cell is described as cylindrical, multinucleated, and striated, which type of muscle is it?

Accepted Answer

Skeletal muscle

Question 19

Which of the following best explains why the heart can continue to beat even when removed from the body and placed in a nutrient solution?

Accepted Answer

Cardiac muscle contains self-stimulating pacemaker cells that generate action potentials.

Question 20

Which of the following is a correct sequence of events for skeletal muscle contraction?

Accepted Answer

Acetylcholine release → depolarization of muscle fiber → calcium release from sarcoplasmic reticulum → actin-myosin interaction

Comparative Study of Skeletal, Cardiac, and Smooth Muscle Types

Study Guide - Practice Questions

Study Guide - Flashcards