The difference between plasma and serum lies in their clotting factors. Plasma and serum are important parts of the blood as well as other formed cells. The plasma concentration in blood is 55% of its total.
Blood is a liquid tissue that circulates through the body of all humans and vertebrates. It is responsible for the distribution of nutrients throughout the body, as well as the defense against infections and gas exchanges.
Plasma: contains fibrinogen, white blood cells, red blood cells, and platelets. Serum: blood serum is the result of clotting the blood and removing the clot. It is the same as blood plasma, although it does not have the coagulation proteins (fibrinogen)
It is composed of formed elements and plasma. The formed elements are; blood cells, which are white blood cells or leukocytes; and cell derivatives, which are red blood cells or erythrocytes and platelets.
Plasma is the liquid in which the formed elements float, and they are distributed throughout the body through capillaries, veins and arteries. Plasma is an isotonic solution, necessary for the survival of the cells it carries. The isotonic solution is one in which the solute concentration is the same outside and inside the cells.
There is a substance called fibrinogen, which is responsible for blood clotting. When the blood is separated and the plasma is removed, it still retains the fibrinogen. When the clotting factors are consumed, the resulting part of the blood is the blood serum, which does not contain extract this fibrinogen.
Differences between plasma and serum
Both serum and plasma are components of blood. Plasma is the aqueous medium of the blood that is obtained after removing red blood cells and white blood cells.
When plasma is removed and allowed to clot, the clot shrinks over time. At that time, the serum is squeezed out, removing the clot. This process is known as electrophoresis.
By eliminating the clotting agent, fibrinoglobulins and plasmas appear in the serum. Commonly, since we only remove the fibrinogen, serum is said to be plasma without a clotting agent.
Plasma
Frozen plasma. Source: DiverDave via Wikimedia Commons
Plasma is the fluid in the blood that has no cells. This is obtained after the blood is filtered and the red blood cells and white blood cells are removed.
The composition of plasma is 90% water, 7% protein and the rest corresponds to fats, glucose, vitamins, hormones, etc. Plasma is the main component of blood, since it is the aqueous medium where substances are kept in solution.
Plasma has a viscosity level 1.5 times that of water. And it covers 55% of the blood volume. With a concentration of 7% of proteins, these are classified into Albumin, Lipoproteins, Globulins and Fibrinogen.
Albumin is the protein that controls the level of water in the blood and that helps transport lipids. Lipoproteins are responsible for buffering changes in pH and responsible for the viscosity of the blood, Globulins, are related to all defense mechanisms that the body has and Fibrinogen, is the main protein of blood clotting.
Plasma proteins carry out different activities within the body. Their most important functions are:
- Oncotic function: they perform the pressure function within the circulatory system that is responsible for maintaining the water level in the blood.
- Buffer function: this function is responsible for maintaining pH levels within the blood. Blood is at pH levels between 7.35 and 7.35.
- Rheological function: This is the function in charge of maintaining the viscosity of the plasma, so that the rest of the cells can move through the bloodstream.
- Electrochemical function: that maintains the balance of ions within the blood.
Serum
Blood components. Source: MesserWoland via Wikimedia Commons
The blood serum or hematic serum is the component of the blood once we remove the fibrinogen. To obtain the serum, we first need to filter the blood to separate the plasma and remove its fibrinogen proteins. These proteins are what allow clotting.
Once we remove its red blood cells, white blood cells and clotting agent from the blood, the result obtained is a liquid composed practically of water with a solution of proteins, hormones, minerals and carbon dioxide. Although serum is blood devoid of practically all its nutrients, it is an important source of electrolytes.
Electrolytes are substances made up of free ions. Maintaining a correct level of electrolytes is extremely important, since it is responsible for maintaining the osmotic function of the body, which affects the regulation of hydration of the body and the maintenance of its pH, being critical for the functions of nerves and muscles..
Blood serum, also known as immune serum, contains plasmase, which is the soluble ferment that can transform fibrinogen into fibrin. In addition to containing fibrinoglobulin that is formed at the expense of fibrinogen when fibrin has been supplied to it.
Uses of plasma and serum
Plasma is primarily used in burn victims to replace blood fluids and proteins. In these cases, the skin loses its ability to retain fluids, so it is necessary to replace lost body fluids.
Similarly, as plasma contains all the coagulant effects, it is used to donate to patients with coagulator deficiency. For this treatment, plasma is used to grow coagulants that are then passed on to patients with coagulant deficiency.
The serum, by removing its clotting agent, maintains a higher concentration of antibodies. This is used in infections, so that the antibodies present in the serum bind to the infectious agent, causing a greater reaction to it. This triggers an immune response from the infected body.
References
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- Johann Schaller, Simon Gerber, Urs Kaempfer, Sofia Lejon, Christian Trachsel (2008) Human Blood Plasma Proteins: Structure and Function. Recovered from google books.
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