Fluid-Phase Components Plasma is mostly water (92%) with salts protein and lipids. Cells can be separated from plasma by centrifugation. Unless an anticoagulant is added to blood at the time of phlebotomy (blood taking) the plasma will gel and form a clot. The fluid remaining after clot formation is called serum.
Plasma protein account for 6% of the plasma volume. These include albumin, immunoglobulins, coagulation (blood clotting) factors and transport proteins. The proteins can be separated and quantitated by electrophoresis.
[1] Albumin helps maintain a constant plasma volume. The high concentration of albumin exerts a strong osmotic pressure that keeps water and solutes within the blood vessels. This osmotic pressure counterbalances intravascular hydrostatic pressure that forces fluids out of the vessels. A low level of albumin will cause excessive leakage of the fluid into the tissues resulting in edema. Albumin also acts as a carrier for various enzymes, hormones, and metabolites.
[2] Immunoglobulins (antibodies) are produces by B-lymphocytes and plasma cells. These protect against infection by binding to microorganisms and attracting macrophages for phagocytosis.
[3] Coagulation protein are required for haemostasis. If any of those factors is reduced, the patient is in danger of hemorrhaging (bleeding), e.g. Factor VIII deficiency causes hemophilia.
[4] Transport Proteins, e.g. transferrin binds and transports iron to the bone marrow for production of hemoglobin, transcobalamin is the carrier protein for vitamin B12, haptoglobin transports free plasma hemoglobin to the liver, lipoproteins transport lipid, cholesterol, and triglycerides.
[The Singapore Polytechnic]
Title : Basic of the Study of Blood 2
Description : Fluid-Phase Components Plasma is mostly water (92%) with salts protein and lipids. Cells can be separated from plasma by centrifugation. Un...
