Sliding Filament Theory Steps

Sliding filament theory for the contraction of skeletal and cardiac muscle(tropomyosin, troponin, myosin binding site, Ca++ channel, Ca++ active transport pumps, ATP, acetylcholine, acetylcholinesterase,
Sliding Filament theory Step 1Action potential (electrical stimulation) from Somatic (motor) nerve, stimulates skeletal muscle fibers (cells) at neuromuscular junction (latent period)
Sliding Filament theory Step 2Action potential causes the opening of potassium (Na+) channels on the sarcolemma thus causing a wave of depolarization to travel from the neuromuscular junction (latent period)

Sliding Filament theory Step 3depolarization event is communicated deep into the sarcoplasm via t-tubules (latent period)
Sliding Filament theory Step 4depolarization of sarcoplasmic reticulum causes the opening of calcium channels and the subsequent release of calcium from sarcoplasmic reticulum (contraction period)
Sliding Filament theory Step 5Calcium binds to troponin, troponin molecules change shape causing tropomyosin, to move off of crossbridge binding sites on actin. (contraction period)
Sliding Filament theory Step 6Myosin crossbridges bind to crossbridge binding sites on actin (contraction period)
Sliding Filament theory Step 7ATPase acts on ATP in the binding site on the myosin to convert it into ADP+ Pi+ Energy (contraction period)
Sliding Filament theory Step 8Released kinetic energy causes a “power-stroke which causes actin to slide over myosin (contraction occurs) (contraction period)
Sliding Filament theory Step 9Sarcolemma repolarizes due to the opening of potassium channels (relaxation period)
Sliding Filament theory Step 10Calcium channels close and an active transport pump carries calcium back to sarcoplamic retculum, troponin returns to pre-calcium shape, and ATP reforms to release the actin-myosin bond. (relaxation period)