Composition of blood:

Blood is a specialized bodily fluid (considered a specialized form of connective tissue) that is composed of a liquid called blood plasma and blood cells suspended within the plasma. The weight of the blood in our body is about 1/12th of our body. The average adult has a blood volume of roughly 5 liters.

In a healthy person, plasma constitutes about 55% of the volume of the blood, and cells or cell-like bodies about 45% of the volume of the blood.