Structure of Skeletal Muscles

Actin

-Thin filaments
-Contraction

Myosin

-Thick filaments
-Contraction

These are both involved in the process of muscle contraction.

Peristalsis

-Movement through a smooth muscle
-Coordinated squeezing movement
-Passage of food

Is a process, and a movement threw smooth muscle. Example for smooth muscle is your esophagus, so you swallow food and it enters into your esophagus the muscular contraction that pushs it down to your stomach on threw to your digestive system. There is a specific type of movement that pushes food threw these circular organs, its called Peristalsis. Similar movement to milking a cow, a movement of up and down threw a tube.

Fascia

-Covering muscle becomes the tendons (only in skeletal muscles)

Fascia the face that it becomes a tendon it should be a dead give away that it is only involved in skeletal muscle. The tendons are necessary to hold the joints together. It is the tendons that holds everything together and stable.

Myofibril

-Muscle fibers
-Contraction

Myofibrils would imply for anything MYO meaning fiber muscle FIBRIL meaning fibers. These are involved in the process of contraction.