Blood plasma: Definition, Functions, Differences, Components and Cells

It is the liquid part that contains blood with an approximate 90% water.

One of its functions is to maintain the hydration of the tissues of the body and it is essential for the cells to stay alive and in good condition.


The Blood Plasma serves as a transport channel for the supply of nutrients to the cells of the various organs of the body, as well as transferring waste derived from cellular metabolism to the kidneys, lungs and liver for their expulsion.

Another function of Blood Plasma is to help distribute heat throughout the body, maintaining biological stability, homeostasis and acid-base balance in the blood and body.

How is blood plasma obtained?

Blood plasma is generated by separating the white blood cells ( leukocytes ), red blood cells (erythrocytes) and platelets (thrombocytes) that represent blood cells.

The main solute of Blood Plasma focuses on a heterogeneous group of proteins that is equivalent to 7% of plasma by weight.

Difference between plasma and extracellular tissue

One of the most notorious differences between plasma and extracellular fluid is the protein content contained in the plasma, which exerts an osmotic effect by which water tends to move from another fluid to the plasma.

Components of Blood Plasma

Plasma is composed of several agents, among which are the clearances, which are linked with the protein molecules and their quantity depends on the meals that the individuals ingest, usually it does not exceed 1 gram per 100 milliliters.

Some plasma components are in low concentration but are of great physiological importance and high turnover, such as glucose or blood sugar.

Glucose is absorbed by the body in the gastrointestinal tract. It can also be released from the liver, thus providing the energy needed by tissue cells.

Several inorganic materials are essential in plasma, and each has special functional attributes.

The predominant cation or positively charged ion in the plasma is sodium, this ion is produced in cells with a lower concentration.

The total volume of extracellular fluid as the amount of sodium in the plasma is regulated by the kidneys.

Unlike potassium or intracellular cation that represents even a much lower value than sodium in plasma.

The concentration of calcium in the plasma is controlled by two hormones: the parathyroid and calcitonin.

Also magnesium, is found in low concentration in the plasma and variations can affect the nervous system, muscles and heart.

The chloride is in the plasma the ion with negative charge and is the main salt.

In summary, plasma is made up of 6-8% of proteins and if it is the inhibitors of coagulation they help to prevent it and to resolve the clots after they are formed. When the plasma is allowed to clot, the fibrinogen becomes fibrin, trapping the cellular elements of the blood.

The resulting liquid, devoid of cells and fibrinogen, is called serum. Plasma and serum biochemical tests are an important part of modern clinical diagnosis and treatment monitoring.

High or low concentrations of glucose in plasma or serum help to confirm serious disorders such as diabetes mellitus and hypoglycaemia .

Electrolytes, cells, among others are also found in plasma.

What are the cells?

Blood cells are divided into 4 types:

  • Red blood cells (erythrocytes).
  • Platelets (thrombocytes).
  • Infocitos.
  • Phagocytic cells.

Phagocytic cells and lymphocytes form white blood cells (leukocytes).

Among the functions of each of the cells is:

  • Red blood cells capture oxygen from the lungs and send it to the tissues.
  • Platelets participate in the formation of blood clots.
  • Lymphocytes are involved with immunity.
  • Phagocytic cells occur in two varieties, granulocytes and monocytes, and ingest and degrade microorganisms and foreign particles.

An average adult with a good state of health can produce approximately 10 billion white blood cells, 200 billion red blood cells and 400 billion platelets per day.