Lecture 13 Flashcards
Terminology associated with the sacromere:
- myosin filament
- actin filament
- cross-bridge
- power stroke
Rate of ATP hydrolysis depends on ….
myosin heavy chain (MHC) type
Type I MHC:
slow hydrolysis rate
Type IIa MHC:
fast hydrolysis rate
Type IIb MHC:
very fast hydrolysis rate
Cross-bridge cycling 4 steps:
- myosin heads split ATP and become reoriented and energized
- myosin heads bind to actin forming crossbridges
- myosin heads rotate toward centre of the sacromere (power stroke)
- as myosin heads bind ATP, the crossbridges detach from actin
MHC I –>
Type I
MHC IIa –>
Type IIA
MHC IIb –>
Type IIB
Biceps brachii is ___% Type I and ____% Type II.
- 50%
- 50%
Deltoid is ___% Type I and ____% Type II.
- 60%
- 40%
Gluteus maximus is ___% Type I and ____% Type II.
- 50%
- 50%
Vastus Lateralis is ___% Type I and ____% Type II.
- 50%
- 50%
Biceps femoris is ___% Type I and ____% Type II.
- 60%
- 30%
Gastrocnemius is ___% Type I and ____% Type II.
- 50%
- 50%
Soleus is ___% Type I and ____% Type II.
- 90%
- 10%
Tibialis anterior is ___% Type I and ____% Type II.
- 70%
- 30%
Erector spinae is ___% Type I and ____% Type II.
- 50%
- 50%
Type I muscle fibre: neural, metabolic, other name.
- slow twitch
- oxidative
- slow oxidative
Type IIa muscle fibre: neural, metabolic, other name.
- fast twitch
- oxidative/glycolytic
- fast oxidative glycolytic
Type IIb muscle fibe: neural, metabolic, other name.
- fast twitch
- glycolytic
- fast glycolytic
Muscle fibre is made up of ______ in ____ and in ____.
- sacromeres
- series
- parallel
Length of muscle =
number of sacromeres in series
Force generated by muscle =
number of sacromeres in parallel