Smooth muscle cells are innervated by the ans which

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Unformatted text preview: s  ­ single unit smooth muscle ContracGon occurs by slight depolarizaGon which results in opening of plasma membrane voltage ­gated Ca2+ channels (The SR contributes very little to the cytosolic Ca2+ influx). Myosin regulated contracGon  ­ Ca2+ acGvates smooth muscle predominantly by regulaGng the phosphorylation state of myosin proteins. RelaxaGon is accomplished by pumping the Ca2+ back out of the cell. Smooth muscle cells are innervated by the ANS, which occurs by diffuse neurotransmi"er release (e.g. ACh, or catecholamines). Vertebrate cardiac muscle Cardiac muscle – Involuntary, Striated Cells are usually uninucleate and branched. They form intercalated discs with adjacent cells. Intercalated discs contain gap juncGons and desmosomes. Specialized pacemaker cells generate endogenous APs Long lasGng APs result from Ca2+ flux across the cell membrane which prolongs depolarizaGon. This ensures prolonged contracGon and coordinated pumping of the heart. Cells have limited glycolyGc capacity and funcGon mainly oxi...
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This note was uploaded on 01/19/2014 for the course PCB 3712 taught by Professor Leighty during the Winter '09 term at University of South Florida - Tampa.

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