Blood  is just like  a fluid which circulates  around our tissues and cells.Blood is continuously pumped by our heart.It has been estimated that about (1/3) cup of blood is pumped along with one single beat.It has its own importance and value.Blood is  made of  45 percent plasma(liquid part  of  blood) and blood cells.The weight of blood in human is approximately (1/12).Blood cells present in blood help the body to maintain  the temperature of  body. It also helps  the cells  to function properly  and to develop improvements in immune system.Apart from this gaseous exchange of gases also takes place through blood.Donating blood  to patients   has its own  value and significance because in this way new cells are generated which can  increase  the sensitivity of blood against antibodies more accuaratly and easily