Stauber Smooth Muscle
Terms
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Anatomy of smooth muscles
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No striations or sarcomeres
Actin and myosin
Gap junction; synctium
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What are the 2 major types of Smooth muscles?
And contraction mech.
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-Multiunit: Located far from each other. Collagen between them. Require nerve stim. NMJ. Large blood vessels, iris of eye, piloerector muscles
-Visceral: Don't need nerve stim. Syncytium. bladder, intestines.
Co
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Regulation of smooth muscle contraction. Myosin.
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-Phosphorylation of MLC cause binding of myosin to actin. Regulates contraction. Relaxatio; removal of phosphate on MLC by myosin phosphatase. (Ratio of activated kinase:phosphatase = degree of contraction)
When LCs ppylt'd,
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Regulation of smooth muscle contraction. Ca activation.
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-Ca activates calmodulin, which activates myosin (by a protein kinase intermediate rxn).
-Activator Ca SR or extracellular pools.
-Na-Ca exchanger to restore Ca homeostasis
-Ca-ATPase; Ca extrusion