What is the primary function of muscles in the body?

This muscle is involuntary and found in the inner walls of our organs and blood vessels. 

bundles of organized muscle fibers inside each skeletal muscle if known as

the point where the tendon of the mm joins the stationary bone.

the outer most layer of the skeletal muscle that decreases friction between other muscles and bones

which muscle group in the agonist in Elbow Flexion -

Biceps__________  Triceps ___________

what is the protective sheath of a single muscle fiber?

Which muscle group is the antagonist in Knee Extension

Hamstrings  /  Quads

Our muscles decrease in size as we age

A muscular disease that can affect a person at any point in their life. It is characterized as the muscles weakening over time with eventual loss of the ability to walk. There is no cure for this disease. 

When lowering your body into a squatting position, what type of muscle contraction are your quadriceps performing?

What muscle group is the agonist when performing Hip Extension

- Iliopsoas/rectus Femoris   /    Gluteus Max 

What is known as an autoimmune disorder affecting the muscles throughout the body with first signs usually showing in the face. This disease has no cure but can be managed with medication. 

When performing a hamstring stretch, my hamstring is performing an eccentric contraction

When a muscle contraction is occurring with movement in the muscle joint, this is known as an