Plasma
- Plasma is a straw-colored, viscous fluid that constitutes nearly 55% of the total blood volume.
- Approximately 90-92% of plasma is water, making it the primary solvent for transporting various substances throughout the body.
- Proteins contribute 6-8% of plasma content, with major proteins including fibrinogen, globulins, and albumins.
- Fibrinogen: Fibrinogen is essential for blood clotting or coagulation. It plays a crucial role in the formation of fibrin, a protein network that stabilizes blood clots.
- Globulins: Globulins primarily participate in the body's defense mechanisms, including immune responses and antibody production.
- Albumins: Albumins help maintain osmotic balance in the blood, regulating the movement of water and solutes between the blood and surrounding tissues.
- Plasma also contains small amounts of minerals such as sodium (Na+), calcium (Ca++), magnesium (Mg++), bicarbonate (HCO3–), chloride (Cl–), etc.
- Glucose, amino acids, lipids, and other nutrients are present in plasma as they are continually in transit throughout the body, serving as energy sources and building blocks for cellular functions.
- Factors necessary for blood coagulation or clotting are present in plasma in an inactive form.
- These factors play a crucial role in the clotting cascade, a series of enzymatic reactions that lead to the formation of blood clots.
- Plasma without the clotting factors is referred to as serum. Serum is obtained by allowing blood to clot and then removing the clotting factors through centrifugation.
- Unlike plasma, serum does not contain clotting factors, making it suitable for certain diagnostic tests and laboratory analyses.