The viscosity of human blood is due to the presence of proteins in the blood. Proteins play a crucial role in maintaining the viscosity and thickness of the blood. They form a major component of the plasma, the liquid part of the blood, and contribute to its overall consistency.
Proteins in the blood, such as fibrinogen and albumin, contribute to the viscosity by interacting with other components in the blood, such as red blood cells, platelets, and white blood cells. These interactions help to create a network or matrix that gives blood its viscosity.
Platelets, which are cell fragments found in the plasma, are responsible for clot formation and do not directly contribute to the viscosity of the blood. Similarly, sodium in serum and the presence of red blood cells and white blood cells do not directly affect the viscosity of the blood.
In summary, while platelets, sodium, red blood cells, and white blood cells play important roles in the functioning of the blood, it is the proteins in the blood that are primarily responsible for the viscosity of human blood.