PHYS30005 Lecture Notes - Lecture 1: Voltage-Dependent Calcium Channel, Serca, Low Frequency
13 Aug 2020
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Not: depletion of ach at the nmj (peripheral fatigue) Impaired serca function in muscle cells: peripheral blockade of voltage gated ca2+ channels. Fatigue: inability to sustain peak contraction over full time period. A: tetanic response doesn"t degrade for each time, ability to evoke contraction is undiminished by trial, voluntary contraction is degrading much faster -> suggest central. B fatigue: evoked tetanic response diminishes over time, something else is limiting the force produced by contraction. Voltage-gated calcium channels (in the sarcolemma) connecting to a ryanodine receptor. In sr is much higher in the interstitial space. Movement of ca2+ from sr to sarcoplasm is facilitated. Diffusion (no atp: ryr is a calcium channel and allows calcium efflux through a diffusion process (into sarcoplasm) Ca2+ reuptake into sr requires atp (serca pump) Damage to sr pump will indirectly impact on ca2+ efflux from sr. Sarcoplasmic reticulum = membrane bound structure within muscle cells store of.
