Q: Which of the following equations best represents the relationship between the strength of muscle contraction and the number of motor units activated?

$$\text{Strength of contraction} = \text{Number of motor units activated}$$

Question 1

Which of the following best describes the primary function of skeletal muscle tissue?

Accepted Answer

Voluntary movement and manipulation of the environment

Question 2

During muscle contraction, which sarcomere band remains unchanged in length?

Accepted Answer

A band

Question 3

What is the role of acetylcholinesterase at the neuromuscular junction?

Accepted Answer

It breaks down acetylcholine, ending muscle stimulation

Question 4

Which connective tissue layer directly surrounds individual muscle fibers (cells)?

Accepted Answer

Endomysium

Question 5

A patient is unable to relax their muscles after contraction. Which process is most likely impaired?

Accepted Answer

Breakdown of acetylcholine by acetylcholinesterase

Question 6

Which of the following is true regarding the H zone of a sarcomere during contraction?

Accepted Answer

It disappears

Question 7

What is the correct sequence of events for muscle contraction after a motor neuron fires?

Accepted Answer

Ach released → Sarcolemma depolarizes → Sarcoplasmic reticulum releases Ca++

Question 8

Which protein directly blocks the myosin binding sites on actin in a resting muscle?

Accepted Answer

Tropomyosin

Question 9

A muscle is required to generate a very fine, precise movement. Which of the following best describes its motor unit organization?

Accepted Answer

Many, small motor units

Question 10

Which of the following best explains why ATP is necessary for muscle contraction?

Accepted Answer

ATP activates myosin and allows it to detach from actin

Question 11

Which of the following equations best represents the relationship between the strength of muscle contraction and the number of motor units activated?

Accepted Answer

$$	ext{Strength of contraction} = 	ext{Number of motor units activated}$$

Question 12

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

Accepted Answer

It contains intercalated discs for cell-to-cell communication

Question 13

Which event occurs immediately after acetylcholine binds to its receptors on the sarcolemma?

Accepted Answer

Ion channels open, leading to depolarization of the muscle cell membrane

Question 14

Which of the following best describes the function of titin in the sarcomere?

Accepted Answer

It binds thick filaments to the Z disc and provides elasticity

Question 15

A muscle is stimulated to contract, but no movement occurs. Which of the following is the most likely explanation?

Accepted Answer

The sarcoplasmic reticulum failed to release Ca++

Question 16

Which of the following best describes the arrangement of myosin molecules in a thick filament?

Accepted Answer

Multiple myosin molecules with heads projecting outward from a central tail region

Question 17

Which of the following is the correct order of muscle connective tissue layers from superficial to deep?

Accepted Answer

Epimysium → Perimysium → Endomysium

Question 18

Which of the following best explains why postural muscles can maintain contraction for long periods?

Accepted Answer

Their large motor units fire at different times, allowing for constant contraction

Question 19

Which of the following best describes the role of Ca++ in muscle contraction?

Accepted Answer

It binds to troponin, causing tropomyosin to move and expose myosin binding sites on actin

Question 20

A muscle has 20 different motor units regulating its cells. According to the study materials, how can this muscle increase the force of its contraction to the greatest extent?

Accepted Answer

By firing all 20 motor units at the same time

Muscle Physiology: Structure and Function of Muscle Tissue

Study Guide - Practice Questions

Study Guide - Flashcards