Under normal resting condition, the heart pumps blood into the aorta 72 times / min. Just as the blood is ejected into the aorta, the aorta swells (distention) a bit, and then contracts with the help of smooth muscles in its wall. A wave is thus created by alternate contraction and dilation of the arteries as the blood moves along. This wave or pulse is regular, recurrent, and palpable (can be felt or seen), and is called pulse. Formation of pulse is pulsation.
The number of pulsation of an artery per minutes is called the pulse rate. The pulse is due to cardiac contraction and expansion. Therefore pulse rate is equal to the heart rate. The difference between systolic and diastolic blood pressure is call pulse pressure.
The pulse rate can decreased or increase according to heart rate. Heart rate is regulated by the pacemarker, and two centres located in a part of the brain called medulla oblongata. These two centres are inhibitory ( to decrease ) and accelerating (increasing) centres. Hormones can also influence heart beat rate.