Question 1

What is the role of tropomyosin in skeletal muscles?

Accepted Answer

A)   Tropomyosin serves as a contraction inhibitor by blocking the actin binding sites on the myosin molecules.
B)   Tropomyosin is the chemical that activates the myosin heads.
C)   Tropomyosin is the receptor for the motor neuron neurotransmitter.
D)   Tropomyosin serves as a contraction inhibitor by blocking the myosin binding sites on the actin molecules.

Question 2

Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments.

Accepted Answer

A) True 
 B)False

Question 3

Most skeletal muscles contain .

Accepted Answer

A)   a predominance of fast oxidative fibers
B)   a predominance of slow oxidative fibers
C)   muscle fibers of the same type
D)   a mixture of fiber types

Question 4

Which of the following statements is most accurate?

Accepted Answer

A)   The I band lengthens during isotonic contraction.
B)   Muscle tension remains relatively constant during isotonic contraction.
C)   T tubules may be sliding during isotonic contraction.
D)   Myofilaments slide during isometric contractions.

Question 5

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?

Accepted Answer

A)   cardiac muscle
B)   multiunit smooth muscle
C)   skeletal muscle
D)   visceral smooth muscle

Question 6

Muscle tissue has all of the following properties except .

Accepted Answer

A)   secretion
B)   contractility
C)   excitability
D)   extensibility

Question 7

The strongest muscle contractions are normally achieved by _ .

Accepted Answer

A)   recruiting small and medium muscle fibers
B)   increasing stimulus above the threshold
C)   increasing stimulus above the treppe stimulus
D)   increasing the stimulation up to the maximal stimulus

Question 8

During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to .

Accepted Answer

A)   hydrochloric acid
B)   a strong base
C)   lactic acid
D)   stearic acid

Question 9

What is the functional unit of a skeletal muscle called?

Accepted Answer

A)   a myofibril
B)   a sarcomere
C)   the sarcoplasmic reticulum
D)   a myofilament

Question 10

What is muscle tension?

Accepted Answer

Muscle tension is th...

Question 11

Which of the following is not a component of the standard treatment for muscle strain?

Accepted Answer

A)   elevation of the limb
B)   rest of the muscle
C)   ice on the muscle
D)   stretching of the muscle

Question 12

The mechanism of contraction in smooth muscle is different from skeletal muscle in that _.

Accepted Answer

A)   ATP energizes the sliding process
B)   actin and myosin interact by the sliding filament mechanism
C)   the site of calcium regulation differs
D)   the trigger for contraction is a rise in intracellular calcium

Question 13

When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands do not diminish in length.

Accepted Answer

A) True 
 B)False

Question 14

In an isotonic contraction, the muscle _ .

Accepted Answer

A)   rapidly resynthesizes creatine phosphate and ATP
B)   changes in length and moves the "load"
C)   never converts pyruvate to lactate
D)   does not change in length but increases tension

Question 15

Which of the following describes the cells of unitary smooth muscle?

Accepted Answer

A)   They are used for vision and hair raising.
B)   They exhibit spontaneous action potentials.
C)   They depend upon recruitment using the autonomic nervous system.
D)   They consist of muscle fibers that are structurally independent of each other.

Question 16

One of the functions of skeletal muscle contraction is production of heat.

Accepted Answer

A) True 
 B)False

Question 17

Fatigued muscle cells that recover rapidly are the products of .

Accepted Answer

A)   slow exercise of short duration
B)   intense exercise of short duration
C)   intense exercise of long duration
D)   slow exercise of long duration

Question 18

Define physiologic muscle fatigue.

Accepted Answer

It is an inability o...

Question 19

Gary was injured in an automobile accident that severed the motor neurons innervating his quadriceps. Even though he has had extensive physical therapy, he is still suffering muscle atrophy. Why is the therapy not working?

Accepted Answer

In denervation atrophy, fibrou...

Question 20

Once a motor neuron has fired, all the muscle fibers in a muscle contract.

Accepted Answer

A) True 
 B)False

Exam 9: Muscles and Muscle Tissue

Define physiologic muscle fatigue.

Correct AnswerverifiedIt is an inability o...View AnswerShow Answer

Which of the following is not a component of the standard treatment for muscle strain?

Correct AnswerverifiedShow Answer

What is muscle tension?

Correct AnswerverifiedMuscle tension is th...View AnswerShow Answer

Gary was injured in an automobile accident that severed the motor neurons innervating his quadriceps. Even though he has had extensive physical therapy, he is still suffering muscle atrophy. Why is the therapy not working?

Correct AnswerverifiedIn denervation atrophy, fibrou...View AnswerShow Answer

One of the functions of skeletal muscle contraction is production of heat.

Correct AnswerverifiedShow Answer

The strongest muscle contractions are normally achieved by _ .

Correct AnswerverifiedShow Answer

Muscle tissue has all of the following properties except .

Correct AnswerverifiedShow Answer

Fatigued muscle cells that recover rapidly are the products of .

Correct AnswerverifiedShow Answer

Once a motor neuron has fired, all the muscle fibers in a muscle contract.

Correct AnswerverifiedShow Answer

Most skeletal muscles contain .

Correct AnswerverifiedShow Answer

During vigorous exercise, there may be insufficient oxygen available to completely break down pyruvic acid for energy. As a result, the pyruvic acid is converted to .

Correct AnswerverifiedShow Answer

Of the following muscle types, which has only one nucleus, no sarcomeres, and rare gap junctions?

Correct AnswerverifiedShow Answer

Which of the following statements is most accurate?

Correct AnswerverifiedShow Answer

Which of the following describes the cells of unitary smooth muscle?

Correct AnswerverifiedShow Answer

What is the functional unit of a skeletal muscle called?

Correct AnswerverifiedShow Answer

Although there are no sarcomeres, smooth muscle still possesses thick and thin filaments.

Correct AnswerverifiedShow Answer

What is the role of tropomyosin in skeletal muscles?

Correct AnswerverifiedShow Answer

In an isotonic contraction, the muscle _ .

Correct AnswerverifiedShow Answer

When a muscle fiber contracts, the I bands diminish in size, the H zones disappear, and the A bands do not diminish in length.

Correct AnswerverifiedShow Answer

The mechanism of contraction in smooth muscle is different from skeletal muscle in that _.

Correct AnswerverifiedShow Answer

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It is an inability o...
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Muscle tension is th...
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In denervation atrophy, fibrou...
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