The Muscular system Flashcards
How much body mass does the muscular system take up? specifically what % in trout?
- majority
- 60% in trout
What are muscles vertically organized into? describe what they look like
- “W-shaped” myomeres
- flat and sheet like
How many sets of muscle myotome are there per vertebrate? What does this do?
- 2 (top and bottom)
- shortens and contracts to generate thrust
Where do muscle myotomes attach to?
- skin and connective tissue
Why are salmon pink?
- diet NOT muscle
What are the primary fuel sources in the production of ATP? What is the dietary fuel source?
- fat + sugar
- proteins
Does glycolysis use oxygen?
- no
What how much ATP is produced in anaerobic production? what is the major biproduct?
- 2
- lactate
Anaerobic glycolysis is ______ as it occurs in ______.
- cytosolic
- cytosol
Oxidative phosphorylation is ______ and occurs in the _____.
- aerobic
- mitochondria
How many ATP are generated in oxidative phosphorylation?
- 30
overall, how much ATP is produced?
- 32 ATP
- lactate
What are the 2 main types of muscle fibre?
- red (0-15%)
- white (vast majority)
What is red muscle fibre?
- bundles - length of fish from head
What is white muscle fibre?
- W shaped myomere
What muscles are dorsal?
- epaxial
What muscles are ventral?
- hypaxial
What is the function of red muscle?
- aerobic endurance (long distance)
- slow speed of contraction
How are red muscle fatigue resistant fibers? (3)
- numerous mitochondria
- high myoglobin content
- slow ATP consumption rate
How do more mitochondria help with fatigue resistance?
- produce ATP
- balanced and efficient
How does myoglobin content help with fatigue resistance?
- buffers/stores + makes O2 available in the muscle
How is ATP supplied in red muscle?
- via oxidative phosphorylation
How do lipid and amino acid stores supply ATP in red muscle?
- largely dietary or muscle wasting at end of life/spawning
How does low glycogen content allow for ATP supply?
- glucose storage form in cell
What is the advantage of red muscle having abundant capillary supply?
- well vascularized (RBC have lots of O2) and high myoglobin/mitochondrial density
Why are red muscle small in diameter?
- low strength contraction (sustained low speed swimming/endurance)
What is the main function of white muscle?
- anaerobic burst (sprint)
How is ATP produced in white muscle? what helps?
- glycolysis
–> high in glycogen (fast twitch glycolytic)
What does high contraction velocity of white muscle do?
- recruits large muscle mass
What does low capillary supply and myoglobin contribute to in white muscle?
- less blood in tissue = LACK OF VASCULARIZATION
White muscle has ___ mitochondria.
- fewer
White muscle is _____. ____x that of red muscle. what does this cause?
- thick
- 2.7x
- causes more tension with contraction
what does increased thickness of white muscle do?
- intensive/burst swimming (SHORT TERM)
- rapid acceleration for catching prey/avoiding predation
What is lactate buildup in white muscle converted back to?
- glucose/glycogen
Since white muscle is anaerobic, this causes ____ ____ and recovery is needed.
oxygen debt
Continuously highly active fish use ____ muscle.
- red
Where is red muscle concentrated in intermittent, sustained high speed swimming fish?
- caudal peduncle (propulsion)
Intermittent burst fish have mainly ____ muscle. But ….
- white
- but have thin band of red muscle
An example of fish using mainly white muscle would be _____ _____ fish.
lie-in-wait
