sinjan

The tissues in our body have the ability of controlling local blood flow. It can increase the blood flow in the local vascular beads, or it can decrease the blood flow in the local vascular blood. the tissue affects the local blood flow independent of the blood flow through the other tissues. Now, the blood vessels are connected in parallel and series. But, I don't understand, how the blood flow is regulated independently in the local tissue without affecting the blood flow to all other tissues. How is it possible? Someone kindly explain. How is the parallel and series connection concept helpful in understanding this. I'm reading Guyton By the way.