https://padlet.com/dapjos680/pds8d2pxlnt9 Events 1,2 and 3 en-us 2019-03-08 15:02:40 UTC 2023-10-14 01:24:26 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Removelove.png dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330853 The brain sends a nerve impulse down to a neuromuscular junction. The nerve impulse causes voltage-gated Ca+ ion channels to open allowing Ca+ ions to enter the neuron. This increase releases Acetylcholine which is released into the cleft. Ach binds to an Ach receptor sight and activates voltage-gated Na+ ion channels which pumps more Na+ ions in and K+ ions out. This imbalance is called depolarization. The depolarization spreads opening voltage-gated Na+ ion channels and eventually initiating an action potential that moves along the lengths of the sarcolemma. Na+ concentrations caused by depolarization stimulate a change in membrane permeability by opening voltage-gated K+ ion pumps which allow K+ to diffuse across the sarcolemma out of the muscle fiber. This is known as repolarization. ]]> 2019-03-08 15:08:21 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330853 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330913 The action potential moves down the sarcolemma and down the T-tubules.

 

]]> 2019-03-08 15:08:28 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330913 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330986 Transmission of the action potential along the T-tubules cause the adjacent sarcoplasmic reticulum to release Ca+ which flows into the cytosol. ]]> 2019-03-08 15:08:33 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339330986 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339331119 Ca2+ combines with Troponin and removes the blocking of Tropomyosin by changing the Actin so that the Myosin binding sites are exposed. The Myosin then binds to Actin and forms cross bridges and contraction begins.

]]> 2019-03-08 15:08:46 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339331119 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339332601 Energized Myosin head attaches to an Actin myofilament, forming a cross bridge.

]]> 2019-03-08 15:11:20 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339332601 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339945949 ADP and P are released and the Myosin head pivots and bends changing to its bent low-energy state. As a result it pulls the Actin filament towards the M line. ]]> 2019-03-11 13:40:41 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339945949 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339947088 After ATP attaches to Myosin, the link between Myosin and Actin weakens, and the Myosin head detaches. ]]> 2019-03-11 13:42:35 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339947088 dapjos680 https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339947745 As ATP is hydrolyzed to ADP and P, the Myosin head returns to its prestroke high-energy or cocked position.]]> 2019-03-11 13:43:42 UTC https://padlet.com/dapjos680/pds8d2pxlnt9/wish/339947745