Blood pressure is the force exerted by circulating blood upon the walls of blood vessels. It is primarily generated by the contraction of the ventricles of the heart, which pumps blood into the arterial system, creating the systolic and diastolic pressure readings.

The average total blood volume in a healthy adult human is approximately 5 liters. This volume can vary based on factors such as body size, age, sex, and overall health status, but 5 liters is the standard physiological estimate used in medical and biological contexts.

The pulmonary circuit is the portion of the cardiovascular system that carries deoxygenated blood away from the right ventricle of the heart to the lungs for gas exchange and returns oxygenated blood to the left atrium. While it involves the heart as a pump, the circuit specifically targets the lungs for oxygenation.

Serum is the clear, yellowish fluid that remains after blood has been allowed to clot. Unlike plasma, which contains fibrinogen and other clotting factors, serum lacks these proteins because they are consumed during the coagulation process. Serum is frequently used in diagnostic testing and immunological studies because it contains antibodies and other dissolved substances without the interference of clotting proteins.