Skeletal Muscle Contraction (14 Steps)

Step 4

Acetycholine (ACh) binds to receptors on the sarcolemma

Step 3

Acetycholine (ACh) release

Step 1

Action potential arrives at the axon terminal

Step 6

Action potential travels down the sarcolemma to the T-tubule

Step 8

Calcium binds to troponin -removes tropomyosin from blocking myosin-binding sites -cannot occur without calcium

Step 7

Calcium release from the sarcoplasmic reticulum (SR)

Step 13

Cocking of the myosin head -due to ATP breaking down to ADP and P

Step 9

Contraction begins

Step 12

Cross bridge detachment -due to ATP binding to the myosin head

Step 10

Cross bridge formation -interaction between actin and myosin

Step 14

Cycling continues -as long as ATP and calcium are present

Step 5

Influx of sodium into the sarcolemma -makes it negatively charged

Step 11

Powerstroke -ADP and P (inorganic phosphate) release

Step 2

Trigger of voltage-gated calcium channels -influx of calcium into the axon terminal