BLOOD

HEMOGLOBIN










Blood performs many important functions within the body including:

Supply of oxygen to tissues (bound to hemoglobin, which is carried in red cells)
Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins (e.g., blood lipids))
Removal of waste such as carbon dioxide, urea, and lactic acid
Immunological functions, including circulation of white blood cells, and detection of foreign material by antibodies
Coagulation, which is one part of the body's self-repair mechanism (the act of blood clotting when one gets cut to stop the bleeding)
Messenger functions, including the transport of hormones and the signaling of tissue damage
Regulation of body pH
Regulation of core body temperature
Hydraulic functions

Blood accounts for 8% of the human body weight,[3] with an average density of approximately 1060 kg/m3, very close to pure water's density of 1000 kg/m3.[4] The average adult has a blood volume of roughly 5 liters (1.3 gal), composed of plasma and several kinds of cells (occasionally called corpuscles); these formed elements of the blood are erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets). By volume, the red blood cells constitute about 45% of whole blood, the plasma about 54.3%, and white cells about 0.7%.



Population Distribution of Major Blood Groups

O + (36.44%)
O - (4.33%)
A + (28.27%)
A - (3.52%)
B + (20.59%)
B - (1.39%)
AB+ (5.06%)
AB- (0.45%)



BLOOD GROUP

A universal donor is someone who can donate blood to anyone else, with a few rare exceptions. The blood type of universal donors is O-. Conversely, a universal recipient can safely take blood from anyone, again with a few rare exceptions. People with AB+ blood are considered universal recipients.