Structure and Composition of Bloods
Structure and Composition of Bloods
Blood consists of blood cells (white blood cells andred blood cells), thrombocyte (plateletes), and blood plasm. Approximately, 55% of blood volume consists of blood plasm. The other 45% consists of blood cells and platelets.
a. Blood Plasm
Blood plasm is the yellow blod fluid. Approximately 92% of plasma is water. Whereas the rest are salt and organic moleculs.
Plasma protein functions in maintaining osmotic pressure and pH of the blood, carrying organic macromollecules, and immunity. Albumin is necessary to maintain blood osmotic pressure and carry bilirubin molecules, whereas globulin in lipoprotein carries cholesterol and form prothrombin and antibody. Part of blood plasma that plays role in body’s immunity is serum. Serum contains various of antibody to fight against antigen.
For example, agglutinin that can coagulate antigen precipitin that causes precipitation when it unites with its antigen. Fibrinogen functions in blood coagulation.
b. Red Blood Cells
Red blood cells (erythrocyte) are the main parts of blood cells. Some characteristics of the red blood cells are the shape is circular, flat, and biconcavedisk; the mature cells have no nucleus; the diameter is less than 0,001 mm; and elastics.
Every mm3 of human blood contains approximately 4-6 millions of red blood cells. Each red blood cell contains 200 millions of hemoglobin (Hb) molecules. With the presence of hemoglobin, the red blood cells can function in carrying O2 and have red color.
c. White Blood Cells
White blood cells (leukocyte) have no color, have nucleus, loose Hb, have irregular shape, mobile, and can change its shape. The ratio number of white blood cells and red blood cells is 1:700. In every millimeter cubic of blood there are 5-11 thousands white blood cells.
d. Platelets
Platelet (thrombocyte) is developed from megrakaryocyte fragmentation in red marrow. The shape is irregular, small in size, colorless, and nucleusless. Everyday our body produces approximately 200 billions of platelets. Our blood contains 150-300 thousands of platelets per mm3.
