https://padlet.com/shabak987/xrbi2jeiam8b Events 1-3 en-us 2019-03-08 15:02:22 UTC 2026-01-14 20:49:14 UTC hello@padlet.com shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328796 The brain sends a nerve impulse also known as action potential through the motor unit. The nerve impulse causes the voltage-gated calcium ion channels to enter. The increase in the calcium stimulates releasing the neurotransmitter, acetycholine (Ach). Ach is then let go into the cleft. Which then activates the voltage-gated Na+ ion channel. This channel pumps more Na+ ions in than K+ ions out which makes the cell depolarized. When the voltage-gated NA+ channel opens it eventually initiates and action potential that moves along the sarcolemma.The Na+ concentrations caused by depolarization stimulate a change by opening voltage-gated K+ ion channels which allows the K+ to diffuse. This is called repolarization.]]> 2019-03-08 15:04:48 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328796 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328872 Step 1:  
Action potential moves down the sarcolemma down the t tubule. 
 

]]> 2019-03-08 15:04:57 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328872 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328922 Step 2: 
This causes the adjacent sarcoplasmic reticulum to release calcium which flows into the cytosol. ]]> 2019-03-08 15:05:02 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339328922 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329084 Step 3 and 4: 
Calcium combines with troponin and removes the blocking of tropomyosin. It's does this by changing the shape of actin so the myosin binding site are exposed. It then binds to actin and forms the cross bridge cycle and contraction starts. 

]]> 2019-03-08 15:05:18 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329084 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329219 step 1: 
The cross bridge formation is high energy myosin heads attaching to actin myofilaments forming a cross bridge cycle. 

]]> 2019-03-08 15:05:31 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329219 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329254 step 2: 
The power stroke is when the myosin head pivots and pulls actin filament toward the M line ]]> 2019-03-08 15:05:36 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329254 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329318 Step 4: 
The next step is clocking of myosin head. This is where energy from hydrolysis of ATP clocks myosin head into an energized state. ]]> 2019-03-08 15:05:41 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329318 shabak987 https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329393 Step 3: 
Then there is cross bridge detachment. This is when ATP attached to myosin head causing the cross bridge to detach ]]> 2019-03-08 15:05:50 UTC https://padlet.com/shabak987/xrbi2jeiam8b/wish/339329393