Biology 3602A/B Lecture Notes - Lecture 29: Myocyte, Gastrocnemius Muscle, Sciatic Nerve

• School: Western University
• Department: Biology
• Course: Biology 3602A/B
• Professor: Jim Staples

Document Summary

# of cross bridges formed at a given time more cross bridges, more strength. These time scales can be within animals, between animals of same species, or among animals over evolutionary time. Acute time scale: how can an individual animal change the muscle contraction strength immediately. Adaptational time scale: some animals have diff muscle strength that has evolved over time. We can change muscle contraction by changing how long the muscle fibre is stim"d for, which will change the # of crossbridges formed. We can also change the stretch of sarcomere and the whole muscle. Can change individual fibres and also change contraction strength of whole organ. But this is a single muscle fibre which is all or none, so how can it get stronger contractions: 4 stimuli in close succession: stronger and stronger contractions. Addition of force from closely spaced stimuli is called summation.