Muscle Contraction by Emily https://padlet.com/emishe822/r0kk45dyiyeb Flow chart of the 3 major events of muscle contraction en-us 2019-03-08 13:18:07 UTC 2023-07-11 03:47:10 UTC hello@padlet.com Event 1 emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891190 Step 1: The brain sends a nerve impulse through the motote unit down to a neuromuscular junction.
Step 2: Nerve impulse causes voltage gated calcium ion channels to open which allow calcium ions to enter the neuron.This increase in calcium stimulates the release of acetylcholine, which is released into the cleft.
Step 3: ACh binds to a ACh receptor site and activates voltage gated sodium channels which pump Na+ in and K+ out. More Na+ is pumped into the muscle cell then K+ is pumped out causing the cell interior to become less negative, or depolarized. 
Step 4: Initial depolarization spreads to adjacent areas, opening voltage gated sodium channels and eventually initiating an action potential the moves along the lengths of the sarcolemma.
Step 5: Na+ concentrations caused by depolarizations, stimulates a change in membrane permeability by opening voltage gated K+ pumps which allow K+ to diffuse across the sarcolemma out of the muscle fiber. This is called repolarization. ]]> 2019-03-11 11:47:38 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891190 Event 2: EC Coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891292 Step 1: The action potentl moves down the sarcolemma and down the T tubules. 

 

]]> 2019-03-11 11:47:49 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891292 Event 2: EC Coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891528 Step 2: Transmission of the action potential along the T tubules cause the adjacent sarcoplasmic reticulum to release Ca2+ which flows into the cytosol. ]]> 2019-03-11 11:48:24 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891528 Event 2: EC Coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891674 Step 3: Ca2+ 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.
Step 4: Myosin binds to actin and forms cross bridges and contraction begins.]]> 2019-03-11 11:48:45 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891674 Event 3: Cross bridge coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891909 Step 1: Myosin cross bridge attaches to the actin myofilament.

]]> 2019-03-11 11:49:26 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339891909 Event 3: Cross bridge coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892254 step 2: Working stroke- the myosin head pivots and bends as it pulled on the actin filament, sliding it towards the M line. ]]> 2019-03-11 11:50:17 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892254 event 3: Cross bridge coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892483 Step 3: As new ATP attaches to the myosin head, the cross bridge detaches]]> 2019-03-11 11:50:53 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892483 Event 3: Cross bridge coupling emishe822 https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892619 Step 4: As ATP is split into ADP and P, cocking of the myosin head occurs.]]> 2019-03-11 11:51:14 UTC https://padlet.com/emishe822/r0kk45dyiyeb/wish/339892619