skeletal muscle in biceps, cardiac muscle in heart, and smooth muscle in small intestine

muscle tissue skeletal biceps cardiac heart smooth small intestine colon myocytes set comparison closeup striated voluntary involuntary sarcomere myofibrils actin myosin contraction fibers function physiology excitability elasticity contractility motor body anatomy medical human muscular vector health science education biology structure anatomical diagram types medicine healthy cell fiber care muscles fitness exercise scientific sport type physical gym training disease