Essay

STEPS OF ACTION POTENTIONAL AND MUSCLE CONTRACTION

Action potential (AP) that was produced at the neuromsucualr juntion is propagated along the sarcoleemma of the skeletal muscle. The depolarization also spreads along the membrane of the T tubules. This causes voltage gated Ca 2+ channels in sarcoplasmic reticulum to open, The CA ions release from the sarcoplasmic reticulumn bin to troponin molecules. The troponin moles bound to F actin (G actin) molecules are relaseed causing tropomyosin to move and expose the active sites on the F actin. Once the active sites on F actin are exposed the heads of the mysoin myofilaments bind to form cross bridges

Action potentional AP that was produced at the nueromusular junction is proppogaed along the sarcolemma. The depolarization spreads along the memrand of the T tubules causing voltages gated Ca 2+ channels in sarcoplasmic reticulumn to open. Ca ions then is released from SR to tropoinin moleculesThe tropoinin molecules that are bound to F actin (G actin) are released allowing typomyosin to move exposing the active sites of the F actin. This will then allow myosin myofilament heads to bind to the exposed active sites causing cross bridges .