muscle function Flashcards
what does creatine phosphate do in muscles
high energy store
what happens during muscle metabolism
rapid changes from very low ATP consumption to high levels of consumption
what happens when 1 molecule of glucose breaks down
2 pyruvates
yielding 2 ATP molecules
what is aerobic cellular respiration
production of ATP in mitochondria
requires oxygen and carbon substrates
Produces CO2, H2O and heat
what happens during muscle fatigue
inability to contract forcefully after prolonged activity
what are the limiting factors in muscle fatigue
Ca2+
Creatine Phosphate
Oxygen
Build-up of acid
Neuronal failure
what happens to oxygen use after exercise
lactic acid converted back to glucose in the liver
creatine phosphate and ATP resynthesized
oxygen binds to deoxymyoglobin
what does slow oxidative mean (SO)
small diameter & red
large amounts of myoglobin and mitochondria
ATP production primarily oxidative
fatigue resistant
what is fast oxidative - glycolytic (FOG) mean?
Large diameter = many myofibrils
Many mitochondria and high glycolytic capacity
what does fast glycolytic fibres mean (FG)
white, fast & powerful and fast fatiguing
For strong, short-term use
what order do muscle fibres get recruited in?
Slow oxidative
Fast oxidative – glycolytic
Fast glycolytic
what is a isotonic contraction
force is constant and the muscle shortens
what is a isometric contraction
length is constant and forces varies
how are the SO/FG fibre ratio determined?
genetically
cardiac muscle has no nerve input, why?
internal pacemaker that can be modified by the autonomic nervous system
