Answer:
The number of liters, or amount of blood that circulates through all the systems of the human body is always a constant one. However, how much of the total amount of blood in the human body passes through the two major circuits (systemic and pulmonary) depends not just on the volume of blood, but also on other factors such as the size of the vessels through which the blood flows and the amount of muscular layers, or any form of tissue, that will offer resistance to that flow. Because pulmonary vessels are smaller in size, and because the need for speed in flow in that circuit is not paramount, as its purpose is to load oxygen and unload CO2 to the lungs, the mean pressure is smaller thain in the systemic flow.
Using, however, the equation on the question, to prove that mean pulmonary blood pressure is 5 times less than that of systemic blood pressure, we would have the following:
1. F= pressure/ systemic resistance
2. Flow= pulmonary flow.
3. Systemic resistance = 5x pulmonary resistance
4. Systemic pressure/ systemic resistance = pulmonary pressure/ pulmonary resistance.
5. Systemic presure x pulmonary resistance/ (5x pulmonary resistance) = Pulmonary pressure.
6. Pulmonary pressure= systemic pressure/5
