Question 1

In the absence of ATP, a contracted muscle can't relax.

Accepted Answer

A) True 
 B)False

Question 2

Slow-twitch fibers contain many mitochondria and are well supplied with blood vessels, and can make ATP as they need it.

Accepted Answer

A) True 
 B)False

Question 3

Contraction of a skeletal muscle cell is initiated by the

Accepted Answer

A)   release of acetylcholine by a neuron terminating at the neuromuscular junction
B)   release of calcium ions by the neuron into the neuromuscular junction
C)   electrical current traveling from the neuron directly into the muscle cell
D)   hormones delivered by the blood supply to the nearby tissue
E)   release of sodium ions by the neuron into the neuromuscular junction

Question 4

A muscle is arranged in bundles of muscle fibers, called ________.

Accepted Answer

The answer of A muscle is arranged in bundles of...

Question 5

A complete cycle of contraction and relaxation of muscle cells due to stimulation by a motor neuron is called a muscle ________.

Accepted Answer

The answer of A complete cycle of contraction and relaxation...

Question 6

When an electrical impulse traveling along a motor neuron arrives at a neuromuscular junction

Accepted Answer

A)   there is an increase in the secretion of acetylcholine at the neuromuscular junction
B)   calcium is transported back to the sarcoplasmic reticulum
C)   sliding of actin and myosin filaments is inhibited
D)   myosin-actin cross-bridges are destroyed
E)   a new electrical impulse is generated that returns the message to the original nerve

Question 7

As the rate of stimulation of motor units of a muscle increases, muscle force increases. This process is known as ________.

Accepted Answer

The answer of As the rate of stimulation of motor...

Question 8

The process of activating more motor units when more force must be exerted is called ________.

Accepted Answer

The answer of The process of activating more motor units...

Question 9

Cardiac muscle differs from skeletal muscle in that

Accepted Answer

A)   all cardiac muscle is under involuntary control
B)   cardiac muscle is capable of relaxation
C)   cardiac muscle contracts in response to an electrical or chemical signal
D)   cardiac muscle is excitable and can shorten
E)   cardiac muscle gets longer rather than shorter when excited

Question 10

The portion of a myofibril from one Z-line to the next is a(n) ________.

Accepted Answer

The answer of The portion of a myofibril from one...

Question 11

In skeletal muscle, potassium ions are stored in the sarcoplasmic reticulum.

Accepted Answer

A) True 
 B)False

Question 12

In order for a muscle contraction to occur, cross-bridges must form between which one of the following structures within a muscle cell?

Accepted Answer

A)   the plasma membrane and the sarcoplasmic reticulum
B)   troponin and tropomyosin
C)   calcium and tropomyosin
D)   acetylcholine and muscle cell receptors
E)   actin and myosin

Question 13

According to the sliding filament mechanism, during a muscle contraction, myosin pulls actin filaments toward the center of a sarcomere, causing the entire sarcomere to shorten.

Accepted Answer

A) True 
 B)False

Question 14

Muscle cells produce lactic acid when they have an inadequate supply of

Accepted Answer

A)   protein
B)   O₂
C)   calcium
D)   actin and myosin
E)   glycogen

Question 15

Using the figure above, identify the parts of the sarcomere.
A) sarcomere
B) actin filament
C) myosin filament
D) Z-line
14) Label A represents a(n) ________.
15) Label B represents a(n) ________
16) Label C represents a(n) ________.
17) Label D represents a(n) ________.

Accepted Answer

14) D 15) ...

Question 16

Muscle cells are located in every organ in the body except the stomach and are essential for any activity that requires movement.

Accepted Answer

A) True 
 B)False

Question 17

Muscle contraction accounts for over 75% of the heat generated by the body.

Accepted Answer

A) True 
 B)False

Question 18

In which one of the following would one expect to find motor units made up of only a few muscle cells?

Accepted Answer

A)   arm muscles
B)   eye muscles
C)   chest muscles
D)   thigh muscles
E)   lower-leg muscles

Question 19

Which sequence lists the structures from largest, most inclusive, to smallest?

Accepted Answer

A)   muscle-thick filament-fascicle-muscle fiber-myofibril
B)   muscle-fascicle-muscle fiber-myofibril-thick filament
C)   fascicle-muscle-myofibril-muscle fiber-thick filament
D)   muscle fiber-myofibril-muscle-fascicle-thick filament
E)   thick filament-fascicle-myofibril-muscle-muscle fiber

Question 20

Since contraction of the hamstrings causes the knee to bend and contraction of the quadriceps causes the knee to extend, these muscles are said to be ________.

Accepted Answer

The answer of Since contraction of the hamstrings causes the...

Exam 6: The Muscular System

In order for a muscle contraction to occur, cross-bridges must form between which one of the following structures within a muscle cell?

Correct AnswerverifiedShow Answer

Muscle cells produce lactic acid when they have an inadequate supply of

Correct AnswerverifiedShow Answer

Using the figure above, identify the parts of the sarcomere. A) sarcomere B) actin filament C) myosin filament D) Z-line 14) Label A represents a(n) ________. 15) Label B represents a(n) ________ 16) Label C represents a(n) ________. 17) Label D represents a(n) ________.

Correct Answerverified14) D 15) ...View AnswerShow Answer

When an electrical impulse traveling along a motor neuron arrives at a neuromuscular junction

Correct AnswerverifiedShow Answer

As the rate of stimulation of motor units of a muscle increases, muscle force increases. This process is known as ________.

Correct AnswerverifiedShow Answer

A muscle is arranged in bundles of muscle fibers, called ________.

Correct AnswerverifiedShow Answer

Since contraction of the hamstrings causes the knee to bend and contraction of the quadriceps causes the knee to extend, these muscles are said to be ________.

Correct AnswerverifiedShow Answer

In which one of the following would one expect to find motor units made up of only a few muscle cells?

Correct AnswerverifiedShow Answer

In skeletal muscle, potassium ions are stored in the sarcoplasmic reticulum.

Correct AnswerverifiedShow Answer

According to the sliding filament mechanism, during a muscle contraction, myosin pulls actin filaments toward the center of a sarcomere, causing the entire sarcomere to shorten.

Correct AnswerverifiedShow Answer

Cardiac muscle differs from skeletal muscle in that

Correct AnswerverifiedShow Answer

In the absence of ATP, a contracted muscle can't relax.

Correct AnswerverifiedShow Answer

Slow-twitch fibers contain many mitochondria and are well supplied with blood vessels, and can make ATP as they need it.

Correct AnswerverifiedShow Answer

Muscle cells are located in every organ in the body except the stomach and are essential for any activity that requires movement.

Correct AnswerverifiedShow Answer

A complete cycle of contraction and relaxation of muscle cells due to stimulation by a motor neuron is called a muscle ________.

Correct AnswerverifiedShow Answer

The process of activating more motor units when more force must be exerted is called ________.

Correct AnswerverifiedShow Answer

The portion of a myofibril from one Z-line to the next is a(n) ________.

Correct AnswerverifiedShow Answer

Contraction of a skeletal muscle cell is initiated by the

Correct AnswerverifiedShow Answer

Muscle contraction accounts for over 75% of the heat generated by the body.

Correct AnswerverifiedShow Answer

Which sequence lists the structures from largest, most inclusive, to smallest?

Correct AnswerverifiedShow Answer

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Using the figure above, identify the parts of the sarcomere. A) sarcomere B) actin filament C) myosin filament D) Z-line 14) Label A represents a(n) . 15) Label B represents a(n) 16) Label C represents a(n) . 17) Label D represents a(n) .

Correct Answer
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14) D 15) ...
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