Question 1

Why is the innervation ratio in the ocular muscles one motor axon per 23 muscle fibers,whereas in the gastrocnemius muscle it is one motor axon per 1000 muscle fibers?

Accepted Answer

A)  There are more nerves in the upper body than in the lower extremities.
B)  The ocular muscles require finer control than moving the legs.
C)  The innervation ratio has to do with the overall size of the muscle--the bigger the muscle,the fewer the muscle fibers per motor axon.
D)  The gastrocnemius muscle contracts much harder than the ocular muscles do.
E)  There are fewer muscle fibers in the gastrocnemius muscle than in the ocular muscles.F) B) and D)
G) A) and D)

Question 2

One motor unit obeys a principle called the all-or-none law.

Accepted Answer

A) True 
 B)False

Question 3

Temperature sensitive neurons in the skin are responsible for initiating shivering.

Accepted Answer

A) True 
 B)False

Question 4

What is the name of a sudden and involuntary muscular contraction,often accompanied by pain?

Accepted Answer

A)  bursitis
B)  sprain
C)  strain
D)  tic
E)  spasmF) C) and D)
G) A) and C)

Question 5

What supplies the energy for muscle contraction?

Accepted Answer

A)  actin
B)  myosin
C)  tropomyosin
D)  ATP
E)  Ca2+F) All of the above
G) B) and E)

Question 6

Skeletal muscle contractions play a role in returning the venous blood to the heart.

Accepted Answer

A) True 
 B)False  True

Question 7

Which muscle injury is characterized by a twisting of a joint leading to swelling and injury?

Accepted Answer

A)  sprain
B)  strain
C)  tendinitis
D)  bursitis
E)  myalgiaF) C) and D)
G) B) and E)

Question 8

List the functions of the skeletal muscles.

Accepted Answer

1.Support of the body.
2.Movement of the bones and other body structures.
3.Maintenance of fluids in the cardiovascular and lymphatic system.
4.Maintenance of a constant body temperature.
5.Protection of the internal organs and the stabilization of joints.

Question 9

Each actin molecule is shaped like a golf club,with a straight portion ending in a globular head.

Accepted Answer

A) True 
 B)False

Question 10

What do smooth,cardiac,and skeletal muscle all have in common?

Accepted Answer

A)  They are all uninucleated.
B)  They are all striated.
C)  They are all found in the walls of blood vessels.
D)  The cells of these muscles are all called muscle fibers.
E)  They all interlock at intercalated disks.F) A) and E)
G) A) and C)

Question 11

What happens when the arrector pili muscles contract?

Accepted Answer

A)  Your head nods "yes."
B)  Your leg kicks out.
C)  The hairs on your skin stand on end.
D)  The blood from your skin is rerouted to your core.
E)  You tap your finger.F) B) and C)
G) A) and D)

Question 12

Of the three types of muscle tissue,which is not striated?

Accepted Answer

A)  smooth muscle
B)  cardiac muscle
C)  skeletal muscle
D)  skeletal and smooth lack striations
E)  cardiac and smooth lack striationsF) A) and B)
G) A) and D)

Question 13

Which of the following injuries is most likely to happen to the ankle?

Accepted Answer

A)  sprain
B)  strain
C)  convulsion
D)  bursitis
E)  muscular dystrophyF) C) and D)
G) B) and C)

Question 14

Leiomyomas are a type of smooth muscle cancer that occurs in the uterine wall.

Accepted Answer

A) True 
 B)False

Question 15

From the outside of a muscle coming in,the first thing encountered would be

Accepted Answer

A)  fasciA.
B)  fascicle.
C)  dense connective tissue.
D)  muscle fiber.
E)  myofibril.F) D) and E)
G) A) and B)

Question 16

Explain the differences between fast-twitch and slow-twitch muscle fibers.

Accepted Answer

Fast-twitch muscle fibers are usually ae...

Question 17

Because the heart beats continuously,cardiac fibers never relax completely.

Accepted Answer

A) True 
 B)False

Question 18

The origin of a muscle is on a stationary bone.

Accepted Answer

A) True 
 B)False

Question 19

When a muscle contracts,the H zone almost disappears.

Accepted Answer

A) True 
 B)False

Question 20

Of the three types of muscle tissue,which has multinucleated fibers?

Accepted Answer

A)  smooth muscle
B)  cardiac muscle
C)  skeletal muscle
D)  both smooth and skeletal muscles
E)  both cardiac and smooth musclesF) None of the above
G) A) and E) C

Exam 13: Muscular System

Why is the innervation ratio in the ocular muscles one motor axon per 23 muscle fibers,whereas in the gastrocnemius muscle it is one motor axon per 1000 muscle fibers?

Correct AnswerverifiedShow Answer

One motor unit obeys a principle called the all-or-none law.

Correct AnswerverifiedShow Answer

Temperature sensitive neurons in the skin are responsible for initiating shivering.

Correct AnswerverifiedShow Answer

What is the name of a sudden and involuntary muscular contraction,often accompanied by pain?

Correct AnswerverifiedShow Answer

What supplies the energy for muscle contraction?

Correct AnswerverifiedShow Answer

Skeletal muscle contractions play a role in returning the venous blood to the heart.

Correct AnswerverifiedTrue

Which muscle injury is characterized by a twisting of a joint leading to swelling and injury?

Correct AnswerverifiedShow Answer

List the functions of the skeletal muscles.

Correct Answerverified1.Support of the body. 2.Movement of the bones and other body structures. 3.Maintenance of fluids in the cardiovascular and lymphatic system. 4.Maintenance of a constant body temperature. 5.Protection of the internal organs and the stabilization of joints.

Each actin molecule is shaped like a golf club,with a straight portion ending in a globular head.

Correct AnswerverifiedShow Answer

What do smooth,cardiac,and skeletal muscle all have in common?

Correct AnswerverifiedShow Answer

What happens when the arrector pili muscles contract?

Correct AnswerverifiedShow Answer

Of the three types of muscle tissue,which is not striated?

Correct AnswerverifiedShow Answer

Which of the following injuries is most likely to happen to the ankle?

Correct AnswerverifiedShow Answer

Leiomyomas are a type of smooth muscle cancer that occurs in the uterine wall.

Correct AnswerverifiedShow Answer

From the outside of a muscle coming in,the first thing encountered would be

Correct AnswerverifiedShow Answer

Explain the differences between fast-twitch and slow-twitch muscle fibers.

Correct AnswerverifiedFast-twitch muscle fibers are usually ae...View AnswerShow Answer

Because the heart beats continuously,cardiac fibers never relax completely.

Correct AnswerverifiedShow Answer

The origin of a muscle is on a stationary bone.

Correct AnswerverifiedShow Answer

When a muscle contracts,the H zone almost disappears.

Correct AnswerverifiedShow Answer

Of the three types of muscle tissue,which has multinucleated fibers?

Correct AnswerverifiedC

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True

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1.Support of the body. 2.Movement of the bones and other body structures. 3.Maintenance of fluids in the cardiovascular and lymphatic system. 4.Maintenance of a constant body temperature. 5.Protection of the internal organs and the stabilization of joints.

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Fast-twitch muscle fibers are usually ae...
View Answer

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C