You can control the muscles moving your fingers but you cannot consciously control contractions of muscles in your heart or stomach. Intuitively, you already know cardiac and smooth muscles are involuntary types. Skeletal, the muscle type attaching to bones can be consciously controlled and therefore is a voluntary type. Skeletal -voluntary muscles attached to skeletal elements and cartilage. Cardiac -involuntary muscles making up the myocardium of the heart.
Some muscles have the ability to contract independently without stimulation by the nervous system.
All muscles are invested with connective tissue elements. Delicate fibers wrap around individual muscle cells as endomysium . Heavier connective tissue with more collagen surrounds groups of muscle fibers as perimysium , dividing each muscle into fascicles. Dense irregular c.t. surrounding entire muscles is epimysium . Collagen fibers of these tissues intermingle to form tight connections between muscles and other body structures.