https://padlet.com/logpea682/l19j5d4sf3bw en-us 2019-03-08 15:02:43 UTC 2025-09-02 19:46:44 UTC hello@padlet.com logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339328957 First the brain sends a nerve impulse or action potential to the neuromuscular junction. Then the nerve impulse causes voltage gated calcium ion channels to open which allow calcium ions to enter the neuron which stimulates the release of acetylcholine into the cleft. Ach binds to its receptor sight ands actuates voltage gated sodium channel which pumps Na+ in and K+ out. causing the interior to become less negative or depolarized. Initial depolarization spreads to adjacent areas, opening voltage gated sodium channels and eventually initiating an action potential that moves along the sarcolemma. then repolarization occurs.]]> 2019-03-08 15:05:06 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339328957 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329020 Step 1:  Action potential moves down the sarcolemma, and down the T - tubules.

 

]]> 2019-03-08 15:05:12 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329020 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329076 Step 2: Transmission of the action potential along the T tubules and cause the adjacent sarcoplasmic reticulum (SR) to release Ca 2+ which flows into the cytosol. ]]> 2019-03-08 15:05:17 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329076 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329175 step 1: Cross-bridge formation

]]> 2019-03-08 15:05:27 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329175 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329237 step 2: Power working stroke ]]> 2019-03-08 15:05:33 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329237 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329342 Step 3: Cross bridge detachment]]> 2019-03-08 15:05:43 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329342 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329661 Step 3 and 4: Ca 2+ combines with troponin and removes the blocking action of tropomyosin by changing the shape of the actin so that the myosin binding sites are exposed. Myosin binds to actin, forms cross bridges and contraction begins.

]]> 2019-03-08 15:06:15 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329661 logpea682 https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329792 Step 4: cocking of the myosin head ]]> 2019-03-08 15:06:26 UTC https://padlet.com/logpea682/l19j5d4sf3bw/wish/339329792