The Muscular system

Question 1

How much body mass does the muscular system take up? specifically what % in trout?

Answer 1

• majority
• 60% in trout

Question 2

What are muscles vertically organized into? describe what they look like

Answer 2

• “W-shaped” myomeres
• flat and sheet like

Question 3

How many sets of muscle myotome are there per vertebrate? What does this do?

Answer 3

• 2 (top and bottom)
• shortens and contracts to generate thrust

Question 4

Where do muscle myotomes attach to?

Answer 4

• skin and connective tissue

Question 5

Why are salmon pink?

Answer 5

• diet NOT muscle

Question 6

What are the primary fuel sources in the production of ATP? What is the dietary fuel source?

Answer 6

• fat + sugar
• proteins

Question 7

Does glycolysis use oxygen?

Answer 7

• no

Question 8

What how much ATP is produced in anaerobic production? what is the major biproduct?

Answer 8

• 2
• lactate

Question 9

Anaerobic glycolysis is ______ as it occurs in ______.

Answer 9

• cytosolic
• cytosol

Question 10

Oxidative phosphorylation is ______ and occurs in the _____.

Answer 10

• aerobic
• mitochondria

Question 11

How many ATP are generated in oxidative phosphorylation?

Answer 11

• 30

Question 12

overall, how much ATP is produced?

Answer 12

• 32 ATP
• lactate

Question 13

What are the 2 main types of muscle fibre?

Answer 13

• red (0-15%)
• white (vast majority)

Question 14

What is red muscle fibre?

Answer 14

• bundles - length of fish from head

Question 15

What is white muscle fibre?

Answer 15

• W shaped myomere

Question 16

What muscles are dorsal?

Answer 16

• epaxial

Question 17

What muscles are ventral?

Answer 17

• hypaxial

Question 18

What is the function of red muscle?

Answer 18

• aerobic endurance (long distance)
• slow speed of contraction

Question 19

How are red muscle fatigue resistant fibers? (3)

Answer 19

• numerous mitochondria
• high myoglobin content
• slow ATP consumption rate

Question 20

How do more mitochondria help with fatigue resistance?

Answer 20

• produce ATP
• balanced and efficient

Question 21

How does myoglobin content help with fatigue resistance?

Answer 21

• buffers/stores + makes O2 available in the muscle

Question 22

How is ATP supplied in red muscle?

Answer 22

• via oxidative phosphorylation

Question 23

How do lipid and amino acid stores supply ATP in red muscle?

Answer 23

• largely dietary or muscle wasting at end of life/spawning

Question 24

How does low glycogen content allow for ATP supply?

Answer 24

• glucose storage form in cell

Question 25

What is the advantage of red muscle having abundant capillary supply?

Answer 25

- well vascularized (RBC have lots of O2) and high myoglobin/mitochondrial density

Question 26

Why are red muscle small in diameter?

Answer 26

- low strength contraction (sustained low speed swimming/endurance)

Question 27

What is the main function of white muscle?

Answer 27

- anaerobic burst (sprint)

Question 28

How is ATP produced in white muscle? what helps?

Answer 28

- glycolysis --> high in glycogen (fast twitch glycolytic)

Question 29

What does high contraction velocity of white muscle do?

Answer 29

- recruits large muscle mass

Question 30

What does low capillary supply and myoglobin contribute to in white muscle?

Answer 30

- less blood in tissue = LACK OF VASCULARIZATION

Question 31

White muscle has ___ mitochondria.

Answer 31

- fewer

Question 32

White muscle is _____. ____x that of red muscle. what does this cause?

Answer 32

- thick - 2.7x - causes more tension with contraction

Question 33

what does increased thickness of white muscle do?

Answer 33

- intensive/burst swimming (SHORT TERM) - rapid acceleration for catching prey/avoiding predation

Question 34

What is lactate buildup in white muscle converted back to?

Answer 34

- glucose/glycogen

Question 35

Since white muscle is anaerobic, this causes ____ ____ and recovery is needed.

Answer 35

oxygen debt

Question 36

Continuously highly active fish use ____ muscle.

Answer 36

- red

Question 37

Where is red muscle concentrated in intermittent, sustained high speed swimming fish?

Answer 37

- caudal peduncle (propulsion)

Question 38

Intermittent burst fish have mainly ____ muscle. But ....

Answer 38

- white - but have thin band of red muscle

Question 39

An example of fish using mainly white muscle would be _____ _____ fish.

Answer 39

lie-in-wait