What will happen if both sympathetic and parasympathetic nerves to heart are cut off?
The pacemaker cells of the earth can stimulate the myocardiocites to contract. During a stressful condition without the stimulation of orto and parasympatethic the CV system cannot adapt and overcome the situation
Since the pans is predominant in humans, the sans effects become predominant ( except in erector pilli ms, sweat glamds)