Adult blood volume is 5 to 6 Liters.
Blood is a red coloured fluid that contains continuously renewing cells like red blood cells which renew every 4 months,
platelets that renew every week and also white blood cells.
The cells are swimming in the liquid part of the blood , the plasma.
The blood carries oxygen by RBCs from the lungs into the tissues to generate energy.
It carries out carbon dioxide to be expired through the lungs.