The Appeal to Nature (also, Biologizing; The Green Fallacy): The contemporary romantic fallacy of ethos (that of Mother Nature) that if something is natural it has to be good, healthy and beneficial. E.g., Our premium herb tea is lovingly brewed from the finest freshly-picked natural T. Radicans leaves.
Found only in the heart, cardiac muscle is responsible for pumping blood throughout the body. Cardiac muscle tissue cannot be controlled consciously, so it is an involuntary muscle. While hormones and signals from the brain adjust the rate of contraction, cardiac muscle stimulates itself to contract.
Quick Answer. The heart and the lungs are the primary organs of the circulatory system. The lungs are responsible for adding oxygen to blood. This oxygen-rich blood is then pumped to the heart, which then circulates it through the arteries to all the tissues throughout the body. Veins then return the blood for the addition of new oxygen and recirculation.