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 1,000 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. 
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. B

Question 2

Fibromyalgia is a temporary condition of achy muscles,usually due to overuse.

Accepted Answer

A) True 
 B)False  False

Question 3

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. 
A)  fascia. 
B)  fascicle. 
C)  dense connective tissue. 
D)  muscle fiber. 
E)  myofibril. A

Question 4

What does the word sarco mean?

Accepted Answer

A)  large 
B)  short 
C)  muscle 
D)  tubule 
E)  smooth 
A)  large 
B)  short 
C)  muscle 
D)  tubule 
E)  smooth

Question 5

List the functions of the skeletal muscles.

Accepted Answer

1.Support of the body.
2.Movement of the

Question 6

In good muscle tone,how many motor units are contracted?

Accepted Answer

A)  none 
B)  some 
C)  all 
D)  5-10% of the motor units 
E)  10-15% of the motor units 
A)  none 
B)  some 
C)  all 
D)  5-10% of the motor units 
E)  10-15% of the motor units

Question 7

What is the difference between a tic and a spasm?

Accepted Answer

A)  A tic is a spasm that can be controlled voluntarily. 
B)  A tic is a strong and very painful spasm, especially of the leg and foot. 
C)  A tic is caused by stretching or tearing of a muscle, while a spasm is just an involuntary contraction. 
D)  A tic is caused by the inflammation of a tendon, while a spasm is just an involuntary contraction. 
E)  A tic refers to achy muscles, usually due to overexercise, while a spasm is just an involuntary contraction. 
A)  A tic is a spasm that can be controlled voluntarily. 
B)  A tic is a strong and very painful spasm, especially of the leg and foot. 
C)  A tic is caused by stretching or tearing of a muscle, while a spasm is just an involuntary contraction. 
D)  A tic is caused by the inflammation of a tendon, while a spasm is just an involuntary contraction. 
E)  A tic refers to achy muscles, usually due to overexercise, while a spasm is just an involuntary contraction.

Question 8

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

Accepted Answer

A) True 
 B)False

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

What structure attaches a muscle to a bone?

Accepted Answer

A)  ligaments 
B)  tendons 
C)  bursae 
D)  sarcolemma 
E)  sarcoplasm 
A)  ligaments 
B)  tendons 
C)  bursae 
D)  sarcolemma 
E)  sarcoplasm

Question 11

What does the word brevis mean when referring to a muscle?

Accepted Answer

A)  large 
B)  small 
C)  huge 
D)  long 
E)  short 
A)  large 
B)  small 
C)  huge 
D)  long 
E)  short

Question 12

What does troponin bind to,and what happens when it binds?

Accepted Answer

A)  Ca2+; tropomyosin shifts 
B)  tropomyosin; the sarcomere relaxes 
C)  acetylcholine; the sarcomere shortens 
D)  ATP; tropomyosin returns to normal position 
E)  T tubules; the sarcomere shortens 
A)  Ca2+; tropomyosin shifts 
B)  tropomyosin; the sarcomere relaxes 
C)  acetylcholine; the sarcomere shortens 
D)  ATP; tropomyosin returns to normal position 
E)  T tubules; the sarcomere shortens

Question 13

What supplies the energy for muscle contraction?

Accepted Answer

A)  actin 
B)  myosin 
C)  tropomyosin 
D)  ATP 
E)  Ca2+ 
A)  actin 
B)  myosin 
C)  tropomyosin 
D)  ATP 
E)  Ca2+

Question 14

What muscle works in a pair with the biceps brachii?

Accepted Answer

A)  the triceps brachii 
B)  the trapezius 
C)  the masseter 
D)  the pectoralis major 
E)  the sartorius 
A)  the triceps brachii 
B)  the trapezius 
C)  the masseter 
D)  the pectoralis major 
E)  the sartorius

Question 15

What is the name of the small gap that separates the axon terminal of a nerve from the sarcolemma?

Accepted Answer

A)  T tubule 
B)  sliding filament 
C)  synaptic cleft 
D)  synaptic vesicle 
E)  sarcoplasmic reticulum 
A)  T tubule 
B)  sliding filament 
C)  synaptic cleft 
D)  synaptic vesicle 
E)  sarcoplasmic reticulum

Question 16

Which of the following is not an energy source for muscle contraction?

Accepted Answer

A)  glycogen 
B)  triglycerides 
C)  glucose 
D)  fatty acids 
E)  starch 
A)  glycogen 
B)  triglycerides 
C)  glucose 
D)  fatty acids 
E)  starch

Question 17

If you lock your knees while standing,you may pass out because of the lack of venous return to the heart.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

What is happening during the latent period of a muscle twitch?

Accepted Answer

A)  The muscle relaxes and returns to its former length. 
B)  Fresh ATP binds to the myosin, causing it to return to its resting position. 
C)  ADP and phosphate are released, and the power stroke of the contraction occurs. 
D)  The myosin-actin cross-bridges are broken and the sarcomere shortens. 
E)  The neurotransmitter is diffusing across the synaptic cleft, causing an electrical signal in the muscle cell. 
A)  The muscle relaxes and returns to its former length. 
B)  Fresh ATP binds to the myosin, causing it to return to its resting position. 
C)  ADP and phosphate are released, and the power stroke of the contraction occurs. 
D)  The myosin-actin cross-bridges are broken and the sarcomere shortens. 
E)  The neurotransmitter is diffusing across the synaptic cleft, causing an electrical signal in the muscle cell.

Question 20

Muscles can only pull; they cannot push.

Accepted Answer

A) True 
 B)False

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 1,000 muscle fibers?

Fibromyalgia is a temporary condition of achy muscles,usually due to overuse.

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

What does the word sarco mean?

List the functions of the skeletal muscles.

In good muscle tone,how many motor units are contracted?

What is the difference between a tic and a spasm?

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

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

What structure attaches a muscle to a bone?

What does the word brevis mean when referring to a muscle?

What does troponin bind to,and what happens when it binds?

What supplies the energy for muscle contraction?

What muscle works in a pair with the biceps brachii?

What is the name of the small gap that separates the axon terminal of a nerve from the sarcolemma?

Which of the following is not an energy source for muscle contraction?

If you lock your knees while standing,you may pass out because of the lack of venous return to the heart.

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

What is happening during the latent period of a muscle twitch?

Muscles can only pull; they cannot push.

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