An advantage of the syringe method is that blood appears in the hub when the vein has been entered.
I am not really sure of this answer, but i think its 9. But i am not 100% sure. Take my answer wisely.
It helps the protection of a body organ let's simplify this a little bit an organ can not just stay in your body fat is a place holder so everything doesnt swish around if you know what i mean. so fat buildes up around organs, tissue, and bones to protect them from harm.
have a good day :)
What circuit are you referring too
