Answer
Smooth muscle and cardiac muscle are involuntary because they are not under our conscious control. They are mainly stimulated by the actions of the autonomic nervous system over which we have no control. The advantages of having involuntary muscles is that we don't have to think about breathing, dilating and constricting our blood vessels, digesting, and our hearts beating all at the same time. The autonomic centers of our brains can monitor certain activities going on inside our body and then decide to constrict or relax certain muscles to maintain the delicate balance of our bodies.
Work Step by Step
Smooth muscle and cardiac muscle are involuntary because they are not under our conscious control. They are mainly stimulated by the actions of the autonomic nervous system over which we have no control. The advantages of having involuntary muscles is that we don't have to think about breathing, dilating and constricting our blood vessels, digesting, and our hearts beating all at the same time. The autonomic centers of our brains can monitor certain activities going on inside our body and then decide to constrict or relax certain muscles to maintain the delicate balance of our bodies.
