How exactly does the body direct blood to a muscle or organ that is under heavy stress at a specific time?


I was working out and I felt my chest get pumped up from benching and I wondered what mechanics allow one muscle to accept way more blood than everything else, when all the blood vessels are connected with nothing blocking blood to go anywhere in the body. How does the body just get more blood to the chest, or send more to the stomach when it’s breaking down a big meal?

In: 5

It’s all part of the circulatory system, but one of the key components are your blood vessels. When you work out your muscles use up the nutrients they store. The blood vessels leading to them dilate (grow larger) so that more blood can flow into them to deliver more nutrients and flush out CO2 that they build up from the exercise.

It the same system (but in reverse) that allows your body to restrict blood flow to non-critical parts (like your fingers and toes) when you get cold, to force blood inward to keep your core body temperature up.

More like: your circulatory system starts pumping more oxygen rich blood generally. And the area needing that resource opens up (dilates) it’s blood vessels to accept more of it.

Blood vessels, especially the smaller ones near muscles and organs that actually deliver the blood to its “final destination” and allow oxygen to be exchanged, are able to change their diameter. They can “close” and “open up”, as it were. The body can regulate which parts are getting more blood by (further) opening blood vessels in one place and closing them in another (not fully close, as you don’t want any body part to get cut off, but relatively speaking).