Write an equation showing the relationship between peripheral resistance, blood flow, and blood pressure.

The blood circulating through the vessels of the circulatory system is responsible for the transport of oxygen and nutrients to the cells, and removal of carbon dioxide and waste from the cells. Apart from this, blood is also responsible for carrying the various hormones secreted by the glands to their target organs, maintaining optimal body pH, fighting against pathogens as a part of humoral immunity, and maintenance of homeostasis.

The blood pressure is defined as the force exerted by blood upon the walls of the blood vessels or the chambers of the heart. The optimal blood pressure is 120 systolic over 80 diastolic, that is 120/80 mmHg, in a normal healthy adult. The peripheral vascular resistance is defined as the ability of the vessels to oppose the flow of the blood flowing in them. This vascular resistance offered is directly dependent on the diameter of the blood vessel.