Question 1

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 2

What ion is responsible for initiating muscle contraction?

Accepted Answer

A) Mg2+ 
B) Ca2+ 
C) H+ 
D) Cl- 
E) Na+ 
A) Mg2+ 
B) Ca2+ 
C) H+ 
D) Cl- 
E) Na+

Question 3

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 4

What is the reservoir for Ca2+ in the body?

Accepted Answer

A) muscles 
B) bones 
C) liver 
D) brain 
E) blood 
A) muscles 
B) bones 
C) liver 
D) brain 
E) blood

Question 5

What is the deltoid muscle shaped like?

Accepted Answer

A) a long thin line 
B) a square 
C) a triangle 
D) a circle 
E) a trapezoid 
A) a long thin line 
B) a square 
C) a triangle 
D) a circle 
E) a trapezoid

Question 6

Which of the following is not a term that refers to how muscles work?

Accepted Answer

A) prime mover 
B) synergists 
C) antagonist 
D) synergism 
E) origin 
A) prime mover 
B) synergists 
C) antagonist 
D) synergism 
E) origin

Question 7

Which of the following is not a phase of a single muscle twitch?

Accepted Answer

A) stimulation period 
B) latent period 
C) contraction period 
D) relaxation period 
E) none of these are phases of a muscle twitch 
A) stimulation period 
B) latent period 
C) contraction period 
D) relaxation period 
E) none of these are phases of a muscle twitch

Question 8

Of the three pathways for supplying ATP to the muscle,which pathway(s)do slow-twitch fibers prefer?

Accepted Answer

A) the creatine phosphate pathway 
B) fermentation 
C) aerobic respiration 
D) the creatine phosphate pathway or fermentation 
E) the creatine phosphate pathway or aerobic respiration 
A) the creatine phosphate pathway 
B) fermentation 
C) aerobic respiration 
D) the creatine phosphate pathway or fermentation 
E) the creatine phosphate pathway or aerobic respiration

Question 9

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 10

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 11

Why are slow-twitch muscles dark?

Accepted Answer

A) They have many more myofibrils per motor unit than fast-twitch fibers. 
B) They are designed for strength and explosions of energy. 
C) They need less blood than fast-twitch fibers. 
D) They contain myoglobin. 
E) They have fewer mitochondria. 
A) They have many more myofibrils per motor unit than fast-twitch fibers. 
B) They are designed for strength and explosions of energy. 
C) They need less blood than fast-twitch fibers. 
D) They contain myoglobin. 
E) They have fewer mitochondria.

Question 12

Jillian is a top level cross country runner due to her having predominantly slow-twitch muscle fibers.

Accepted Answer

A) True 
 B)False

Question 13

One motor neuron activates one muscle fiber.

Accepted Answer

A) True 
 B)False

Question 14

What is the name of the muscle that is responsible for blinking and winking?

Accepted Answer

A) latissimus dorsi 
B) trapezius 
C) pectoralis major 
D) orbicularis oculi 
E) extensor digitorum 
A) latissimus dorsi 
B) trapezius 
C) pectoralis major 
D) orbicularis oculi 
E) extensor digitorum

Question 15

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 16

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 sarcome 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 sarcome shortens 
D) ATP,tropomyosin returns to normal position 
E) T tubules,the sarcomere shortens

Question 17

Explain the structural differences between the thick and thin myofilaments.

Accepted Answer

Thick filaments are composed of several

Question 18

Which of the following is not a function of skeletal muscles?

Accepted Answer

A) pumping of blood throughout the body 
B) support 
C) movement of bones 
D) maintenance of body temperature 
E) protection of internal organs 
A) pumping of blood throughout the body 
B) support 
C) movement of bones 
D) maintenance of body temperature 
E) protection of internal organs

Question 19

Of the three pathways for obtaining ATP for muscle contraction,which one requires oxygen?

Accepted Answer

A) only the creatine phosphate pathway 
B) only fermentation 
C) only respiration 
D) fermentation and respiration 
E) the creatine phosphate pathway and fermentation 
A) only the creatine phosphate pathway 
B) only fermentation 
C) only respiration 
D) fermentation and respiration 
E) the creatine phosphate pathway and fermentation

Question 20

Muscles can only pull;they cannot push.

Accepted Answer

A) True 
 B)False

Exam 13: Muscular System

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

What ion is responsible for initiating muscle contraction?

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

What is the reservoir for Ca2+ in the body?

What is the deltoid muscle shaped like?

Which of the following is not a term that refers to how muscles work?

Which of the following is not a phase of a single muscle twitch?

Of the three pathways for supplying ATP to the muscle,which pathway(s)do slow-twitch fibers prefer?

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

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

Why are slow-twitch muscles dark?

Jillian is a top level cross country runner due to her having predominantly slow-twitch muscle fibers.

One motor neuron activates one muscle fiber.

What is the name of the muscle that is responsible for blinking and winking?

What does the word sarco mean?

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

Explain the structural differences between the thick and thin myofilaments.

Which of the following is not a function of skeletal muscles?

Of the three pathways for obtaining ATP for muscle contraction,which one requires oxygen?

Muscles can only pull;they cannot push.

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