muscle contraction steps

muscle contraction step 10

Myosin head pivots (pulling actin)

muscle contraction step 12

Myosin re-extends into "ready" position (ATP->ADP+Pi)(ADP is bound to myosin)

muscle contraction step 11

Myosin releases from actin (cross bridge is broken)(another ATP binds to myosin)

muscle contraction step 1

Neuron action potential arrives at end of motor neuron

muscle contraction step 4

Permeability of sarcolemma changes (Na rushes in)(an action potential is produced)

muscle contraction step 8

Troponin changes shape and shifts tropomyosin to expose binding sites of actin

muscle contraction step 9

myosin binds to actin (cross bridge is formend)(ADP released from myosin)

muscle contraction step 6

release of Ca from the cisternae of the sarcoplasmic reticulum

muscle contraction step 7

CA binds to troponin

muscle contraction step 5

Muscle action potential sweeps into the T tubules triggering

muscle contraction step 2

ACH is released

muscle contraction step 3

ACh binds to receptors on motor end plate