help  | about  | cite  | software

Pathway : Cardiac muscle contraction

Identifier  04260 Description  Contraction of the heart is a complex process initiated by the electrical excitation of cardiac myocytes excitation-contraction coupling, ECC In cardiac myocytes, Ca2 influx induced by activation of voltage-dependent L-type Ca channels DHP receptors upon membrane depolarization triggers the release of Ca2 via Ca2 release channels ryanodine receptors of sarcoplasmic reticulum SR through a Ca2 -induced Ca release CICR mechanism Ca2 ions released via the CICR mechanism diffuse through the cytosolic space to contractile proteins to bind to troponinC resulting in the release of inhibition induced by troponinI The Ca2 binding to troponinC thereby triggers the sliding of thin and thick filaments, that is, the activation of a crossbridge and subsequent cardiac force development and/or cell shortening Recovery occurs as Ca2 is pumped out of the cell by the Na/Ca2 exchanger NCX or is returned to the sarcoplasmic reticulum SR by sarcoendoplasmic Ca2 -ATPase SERCA pumps on the non-junctional region of the SR

1 Data Sets

155 Genes

0 Proteins