What is the specific function of the cardiac muscle?

The specific function of the cardiac muscle is to perform rhythmic contraction and relaxation with the contraction and relaxation of various chambers of the heart, thus pumping the oxygenated blood (blood carrying oxygen) to each and every cell of the body and collecting deoxygenated blood (blood carrying carbondioxide) from each and every cell and then pumping the deoxygenated blood towards the lungs for exhalation of carbondioxide.