Define blood and write its functions.

Blood is a liquid connective tissue that is slightly alkaline with a pH of 7.4. It is composed of 2 parts, liquid and solid. The liquid part of blood is plasma and solid part consists of cells. The blood plasma forms 55% part of blood with 92% water in it and 8% organic and inorganic substances. The main function of blood is transporting oxygen to tissues, transporting nutrients like glucose, amino acids and fatty acids, regulation of body pH, removal of wastes like carbon dioxide, urea and lactic acid.