The smoothing technique is used in this part II to study the cardiac output control in normotensive and hypertensive subjects. It is proved that: 1. cardiac frequency and total blood volume are both determinants of cardiac output in the normotensives; 2. in the hypertensives, blood volume is the main factor, the role of the frequency becomes negligible; 3. at high pressures, the part of the blood volume in the body-weight increases, suggesting an overhydration phenomenon in essential human hypertension.