Last revised by Daniel J Bell on 21 Jul 2021

Blood is a connective tissue usually found in a liquid phase; it comprises a fluid component called plasma (about 55% of the total volume), in which lies the cellular component, comprising several cell lineages, primarily the white blood cells, red blood cells and platelets. In an average adult male the total volume of blood is ~5.5 liters.


Plasma is predominantly composed of water (about 90%) in which both organic substances (such as amino acids, proteins and glucose) and inorganic salts are dissolved. Its physiological pH is slightly basic: 7.4.

ADVERTISEMENT: Supporters see fewer/no ads