Question 1

Which of the following best describes a key structural difference between smooth muscle cells and skeletal muscle cells?

Accepted Answer

Smooth muscle cells lack striations, while skeletal muscle cells display prominent striations.

Question 2

Which of the following statements about the contractile mechanisms of skeletal and smooth muscle is correct?

Accepted Answer

Skeletal muscle contraction is regulated by calcium binding to troponin, while smooth muscle contraction is regulated by calcium binding to calmodulin.

Question 3

A patient is experiencing involuntary contractions in the walls of their digestive tract. Which type of muscle is primarily responsible for this action?

Accepted Answer

Smooth muscle

Question 4

Which equation correctly represents the relationship between force ($$F$$), cross-sectional area ($$A$$), and stress ($$\sigma) in $$muscle tissue?

Accepted Answer

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

Question 5

Which of the following best distinguishes unitary (single-unit) smooth muscle from multi-unit smooth muscle?

Accepted Answer

Unitary smooth muscle cells are connected by gap junctions, allowing coordinated contraction, while multi-unit smooth muscle cells lack gap junctions and contract independently.

Question 6

During muscle contraction, which ion plays a critical role in both skeletal and smooth muscle activation?

Accepted Answer

Calcium ($$Ca^{2+})$$

Question 7

Which of the following scenarios best illustrates the functional difference between unitary and multi-unit smooth muscle?

Accepted Answer

Coordinated contraction of the uterus during childbirth is due to unitary smooth muscle, while precise control of airway diameter in the bronchi is due to multi-unit smooth muscle.

Question 8

Which of the following is a correct statement regarding the microscopic anatomy of smooth muscle cells?

Accepted Answer

Smooth muscle cells have a spindle-shaped appearance and a single central nucleus.

Question 9

Which process is primarily responsible for the activation of skeletal muscle contraction?

Accepted Answer

Release of acetylcholine at the neuromuscular junction

Question 10

A researcher is studying the rate of contraction in smooth muscle versus skeletal muscle. Which of the following statements is most accurate?

Accepted Answer

Skeletal muscle contracts more rapidly than smooth muscle because of its organized sarcomere structure.

Question 11

Which of the following best explains why smooth muscle can maintain contraction for longer periods with less energy expenditure compared to skeletal muscle?

Accepted Answer

Smooth muscle uses the latch-bridge mechanism, allowing sustained contraction with minimal ATP consumption.

Question 12

Which formula represents the calculation of muscle tension ($$T) $$generated by a muscle fiber given force ($$F) $$and lever arm length ($$r$$)?

Accepted Answer

$$T = F 	imes r$$

Question 13

Which of the following is a unique feature of multi-unit smooth muscle compared to unitary smooth muscle?

Accepted Answer

Multi-unit smooth muscle cells are individually innervated, allowing fine control of contraction.

Question 14

Which of the following best describes the activation mechanism of smooth muscle?

Accepted Answer

Activation can be triggered by hormones, stretch, or autonomic nervous system input.

Question 15

Which of the following is a correct comparison between the gross anatomy of skeletal and smooth muscle?

Accepted Answer

Skeletal muscle is attached to bones and responsible for voluntary movement, while smooth muscle is found in the walls of hollow organs and responsible for involuntary movement.

Chapter 9 part 3 Study Guide

Guida di studio - Domande di pratica

Study guide - Flashcard