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.
1 They have thicker walls than the atria, and they create higher blood pressures to pump blood out of the heart into circulation to the body and the lungs.  The right ventricle pumps deoxygenated blood into pulmonary circulation. The left ventricle pumps oxygenated blood into systemic circulation.