What Are the Functions of Blood Plasma?
The primary function of plasma is to carry blood cells, transport substances necessary for human activities, and remove waste products generated within the body. Plasma is a crucial component of blood, containing proteins, inorganic salts, sugars, amino acids, lipids, metabolic waste, and a significant amount of water. Under normal conditions, the regulatory role of the human body maintains a balanced state of plasma components. Therefore, changes in plasma composition can serve as a basis for diagnosing diseases.
Plasma functions primarily as a carrier for blood cells, transporting substances required for maintaining vital life activities and removing waste products produced within the body. Plasma can be considered analogous to the intercellular matrix of connective tissue. It is a pale yellow liquid (due to the presence of bilirubin) and a significant component of blood.
The chemical composition of plasma consists of approximately 90-92% water, with the remaining 10% primarily composed of dissolved plasma proteins. Other components include electrolytes, nutrients, enzymes, hormones, cholesterol, and other vital elements. Plasma proteins are a general term for various proteins and can be classified into three categories: albumin, globulin, and fibrinogen, through salting-out methods.
The functions of plasma include:
1. Maintaining colloidal osmotic pressure in the plasma, contributing to the formation of the blood buffering system and participating in maintaining blood acid-base balance. Plasma proteins, as hydrophilic colloids, facilitate the transportation of nutrients and metabolites by binding to substances that are difficult to dissolve in water, making them soluble.
2. Participating in coagulation and immune responses. The inorganic salts in plasma primarily exist in an ionic state, with an equal total amount of positive and negative ions, maintaining electrical neutrality. These ions play crucial roles in maintaining plasma crystalloid osmotic pressure, acid-base balance, and normal excitability of the nervous and muscular systems.
