First the impulse arrives from the brain then acetylcholine is released along with calcium to attach to the troponin and move the tropomyosin out of the way to create binding sites. Then myosin heads can bind with the actin filaments to form a cross bridge. The myosin head cocks back and then moves forward using ATP. This pulls the filaments together and that is the contraction of the muscle.

Step 4: The acetylcholine moves into the synaptic cleft and binds to the receptors in the channels

Step 3: Calcium entering causes the synaptic vesicles to release the acetylcholine that it's storing.

Step 6: Sodium ions enter the muscle fiber same time while potassium ions are released from the muscle fiber this causes the muscle membrane to become less negative

Step 2: Calcium channels open within the axon terminal, this allows the sarcoplasmic reticulum to go into the axon terminal

Step 7: Once the muscle membrane reaches a certain threshold value action potential spreads across the sarcolemma

Step 1: Impulse travels down motor neuron to the axon terminal (end)

Fascia is a dense connective tissue that separates each muscle from each other

aponeuroses is sometimes used in the body to connect muscles, it is a broad sheet of CT

Epimysium is a layer of CT that is found around each skeletal muscle

Perimysium surrounds each bundle of skeletal muscle fibers called fascicles

I bands are made up of actin filaments and are anchored to the z lines

A bands are made of overlapping filaments (thick and thin)

In the center of the a band is the h zone which is made up of just myosin filaments

The M line is in the middle of the h zone and it consists of proteins that hold the myosin filaments together