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Muscles - Anatomy & Physiology (view source)
Revision as of 10:04, 24 July 2008
, 10:04, 24 July 2008no edit summary
***This causes inhibition of the steric block keeping Actin and Myosin from interacting
***This causes inhibition of the steric block keeping Actin and Myosin from interacting
*Increased Calcium causes a negative feedback inhibition of Ca release, and it is pumped back into the sarcoplasmic reticulum by the Ca/ATPase pump
*Increased Calcium causes a negative feedback inhibition of Ca release, and it is pumped back into the sarcoplasmic reticulum by the Ca/ATPase pump
==Smooth Muscle==
[[Image:Smooth Muscle 1.jpg|thumb|right|150px|Smooth muscle - Copyright RVC 2008]]
*Smooth muscle lacks troponin
*Control of smooth muscle contraction involves '''thin and thick filament regulation'''
* Thin filament regulation is carried out by the actin binding protein, '''Caldesmon''', which binds the thin filament and blocks myosin access
**'''Calmodulin''' (activated by binding Ca) binds caldesmon and causes its dissociation from actin, enabling contraction
*Thick filament regulation occurs by the '''phosphorylation''' of the '''regulatory light chain (RLC)'''
**Calmodulin-Ca binds and activates myosin light chain kinase (MLCK)
**MLCK then phosphorylates RLC, turning myosin on
**Myosin light chain phosphatase (MLCP) switches myosin off
==Cardiac Muscle==
==Cardiac Muscle==
*Structural: striated but uninucleate, highly vascularized
*Structural: striated but uninucleate, highly vascularized
*Gap junctions concentrated at intercalated discs
*Gap junctions concentrated at intercalated discs
*Action potential has a prolonged plateau phase
*Action potential has a prolonged plateau phase
==Tendon==
==Tendon==