Plasma is the pale yellow liquid part of the blood, making up about 55% of its volume. It is about 90% water. Water is a good solvent and has a high specific heat capacity, which makes plasma well suited to transport.Substances carried in solution in the plasma include:• nutrients: glucose, amino acids, fatty acids and glycerol, vitamins
• mineral ions: sodium, potassium, chloride, calcium and hydrogencarbonate
• hormones, such as insulin and adrenaline, carried from endocrine glands to target cells
• waste products: urea from the liver to the kidneys, and most of the carbon dioxide, mainly as hydrogencarbonate ions
• a small amount of dissolved oxygenPlasma also contains plasma proteins:• albumin: the most abundant; lowers the water potential of the blood, helping to draw tissue fluid back into the capillaries, and carries some substances
• globulins: include antibodies, which are part of the immune response
• fibrinogen and other clotting factors, needed for blood clottingPlasma also distributes heat from active organs such as the liver and muscles to the rest of the body and to the skin, where it can be lost. Plasma proteins and hydrogencarbonate ions act as buffers, helping to keep blood pH close to 7.4.Serum is plasma from which the clotting proteins, including fibrinogen, have been removed. At capillaries, plasma is pushed out through the walls to form tissue fluid, which bathes the cells; the large plasma proteins stay behind in the blood.
• mineral ions: sodium, potassium, chloride, calcium and hydrogencarbonate
• hormones, such as insulin and adrenaline, carried from endocrine glands to target cells
• waste products: urea from the liver to the kidneys, and most of the carbon dioxide, mainly as hydrogencarbonate ions
• a small amount of dissolved oxygenPlasma also contains plasma proteins:• albumin: the most abundant; lowers the water potential of the blood, helping to draw tissue fluid back into the capillaries, and carries some substances
• globulins: include antibodies, which are part of the immune response
• fibrinogen and other clotting factors, needed for blood clottingPlasma also distributes heat from active organs such as the liver and muscles to the rest of the body and to the skin, where it can be lost. Plasma proteins and hydrogencarbonate ions act as buffers, helping to keep blood pH close to 7.4.Serum is plasma from which the clotting proteins, including fibrinogen, have been removed. At capillaries, plasma is pushed out through the walls to form tissue fluid, which bathes the cells; the large plasma proteins stay behind in the blood.