PSL301H1 Lecture Notes - Lecture 7: Adenylyl Cyclase, T Wave, Serca
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PSL301H1 Full Course Notes
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The movement of na, ca and k ions lead to one of the most used clinical tests, ecg. 1) the action potential spreads through the muscle fiber"s network of t-tubules, depolarizing the inner portion of the muscle fiber open na+ channels close. 2) voltage (sensitive) gated l-type ca2+ channels open due to depolarization, ca2+ enters the cell. Calcium concentration in the extracellular matrix is 2-5 millimolar. Calcium concentration, generally in most cells, is 1-2 micromolar a thousand fold difference between extracellular and intracellular. 3) ca2+ flows along the gradient, inducing ca2+ release via. Ryanodine receptor channels (ryr) on the sarcoplasmic reticulum. Calcium concentration in the sr is 0. 5 millimolar. 6) ca2+ ions bind to tropin c, tropin t pulls the inhibitory troponin, tropin i, away and opens a pocket for myosin head to bind, leading to contraction. 7) relaxation happens when ca2+ unbinds from tropin c. 8) ca2+ is pumped back into the sarcoplasmic reticulum for storage.
