BIOL 031 Lecture Notes - Lecture 17: Endoplasmic Reticulum, Phosphocreatine, Metabolic Pathway
17 Sep 2020
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Document Summary
Understand how fatigue changes the mechanics of muscular contractions, and describe potential mechanisms of fatigue. Fatigue is the decline in muscle tension as result of previous muscle activity. Associated with decreased shortening velocity (slowing of muscle) and increased relaxation time. Peripheral fatigue a decrease in muscle force can occur in presence of central stimulation (drive) Central fatigue: cns chooses not to activate fully because we are lifting too much (injury prevention) Ca2+ handling: decrease in the rate of release, reuptake, and storage of. Thin filament ca2+ sensitivity: given from a given amount of ca2+ release, less force is generated. Due to binding to troponin, tropomyosin moving out of the way. Inhibition of cross-bridge formation and powerstroke: steps associated with cross-bridge cycle inhibited by mass-action and metabolit driven modulation. Muscle damage-> high tension and leaky sarcoplasmic reticulum cause damage/degradation of contractile proteins. Substrate depletion creatine phosphate depletion for high-intensity exercise, glycogen depletion for long-duration exercise.
