Muscular System

Question 1

What is the basic structural and functional unit of a muscle fiber responsible for contraction?

Answer 1

Sarcomere

Question 2

In the organization of muscle fibers, what refers to the dark bands that extend the length of myosin myofilaments within the sarcomere?

Answer 2

A (anisotropic) bands

Question 3

In the organization of muscle fibers, what refers to the light bands that only contain actin myofilaments?

Answer 3

I (isotropic) bands

Question 4

What type of connective tissue is epimysium?

Answer 4

Dense irregular connective tissue

Question 5

What refers to the bundle of muscle fibers?

Answer 5

Muscle fascicles

Question 6

What covers the bundle (fascicles) of muscle fibers?

Answer 6

Perimysium

Question 7

What type of connective tissue is perimysium?

Answer 7

Dense irregular connective tissue

Question 8

What refers to the plasma membrane that surrounds a muscle fiber?

Answer 8

Sarcolemma

Question 9

What is the rope-like connective tissue that connects the muscle to the bone?

Answer 9

Tendon

Question 10

What type of connective tissue is endomysium?

Answer 10

Areolar connective tissue

Question 11

What is the distance from one Z disc to another Z disc?

Answer 11

Sarcomere

Question 12

What proteins attach thick myofilaments to the Z disc?

Answer 12

Titin

Question 13

What proteins attach thin myofilaments to the Z disc?

Answer 13

Nebulin

Question 14

What is the distance between one thin filament and another thin filament within a sarcomere?

Answer 14

H zone

Question 15

What is the function of tropomyosin?

Answer 15

Tropomyosin covers the active site in the twisted F-actin strands during rest to prevent the binding of myosin heads.

Question 16

What is the neurotransmitter that initiates depolarization that stimulates muscle contraction?

Answer 16

acetylcholine

Question 17

What initiates the release of the neurotransmitter acetylcholine from the synaptic cleft into the presynaptic cleft?

Answer 17

Calcium ions

Question 18

What refers to the invaginations in the sarcolemma?

Answer 18

Transverse tubule

Question 19

True or False.

During contraction, the thick and thin filaments become shorter.

Answer 19

False.

Thick and thin filaments don’t change their length during contraction.

Question 20

What refers to the dark cross-bands present in cardiac muscle tissues that represent the attachment sites between adjacent cells?

Answer 20

Intercalated discs

Question 21

What is the principal energy source for resting muscles or muscles undergoing long-term exercise?

Answer 21

Aerobic respiration

Question 22

During a sprint, what kind of respiration can be a source of ATP?

Answer 22

Anaerobic respiration