Blood types

                                    Blood is a specialized fluid connective tissue in which there is liquid intercellular substance (plasma) and formed elements - (RBC,WBC and platelets ) suspended in the plasma which circulates in closed system of blood vessels. It is red , thick and slightly alkaline.
                     Blood is circulated around the body through blood vessels by the pumping action of the heart.
In animals with lungs, arterial blood carries oxygen from inhaled air to the tissues of the body, and venous blood carries carbon dioxide, a waste product of metabolism produced by cells, from the tissues to the lungs to be exhaled.

Blood is composed of -

                   A. Cellular substances:  45% (42%-45%)

                                                        1)  Erythrocytes or red blood corpuscles (RBC) 

                                                        2)  Leukocytes or white blood corpuscles (WBC)

                                                        3)  Platelets or thrombocytes. 

                   B. Liquid intercellular substance : i.e. plasma -55%(55%-58%) -

                                                                    Plasma contains -

1) Liquid( 91-92%)- water

2) Solid :(8-9%)

Blood 

Properties of Blood 

1) Blood volume : 5-6 liters

2) Normal reaction : Slightly alkaline , pH =7.36-7.45

3) Specific gravity : 1.052- 1.060

4) Viscosity : 4.5 times more viscus than water. 

5) Temperature : 36-38'c

6) Osmotic pressure : Average 25 mm of Hg .

7) Colour    : Red , due to presence of hemoglobin inside RBC.

8) Taste : Salty. 

Blood cell