Hi, I'm having trouble understanding how P, F, and R are related in the human circulation. I know Pressure gradient = Flow x Resistance. But is the flow constant throughout the different vessels. If not, how can we use this equation. Why is there more blood pooled in the veins?, is it due to a slower flow rate or because the veins are more compliant? I'm trying to create an anology between the human circulation and an electrical circuit, if someone has one that would be greatly appreciated. Why is blood in the arteries more pulsatile than blood in the veins? Thank you.