The osmotic pressure of the plasma affects the mechanics of the circulation in several ways. For example, a 1 molar solution of a substance contains 6.022 ×10 23 molecules per liter of that substance and at 0 ☌ it has an osmotic pressure of 2.27 MPa (22.4 atm). The osmotic pressure of solution is determined by the number of particles present and by the temperature. The viscosity of normal plasma varies with temperature in the same way as does that of its solvent water a 5 ☌ increase of temperature in the physiological range reduces plasma viscosity by about 10%. Typical values for the viscosity of normal human plasma at 37 ☌ is 1.4 mN Normal blood plasma behaves like a Newtonian fluid at physiological rates of shear. The presence of these formed elements and their interaction with plasma molecules are the main reasons why blood differs so much from ideal Newtonian fluids. The formed elements are platelets, white blood cells, and red blood cells. The plasma contains 91.5% water, 7% proteins and 1.5% other solutes. Blood is composed of plasma and formed elements. The study of the blood flow is called hemodynamics, and the study of the properties of the blood flow is called hemorheology.īlood is a complex liquid. Because blood vessels are not rigid tubes, classic hydrodynamics and fluids mechanics based on the use of classical viscometers are not capable of explaining haemodynamics. īlood is a non-Newtonian fluid, and is most efficiently studied using rheology rather than hydrodynamics. Hemodynamics explains the physical laws that govern the flow of blood in the blood vessels.īlood flow ensures the transportation of nutrients, hormones, metabolic waste products, oxygen, and carbon dioxide throughout the body to maintain cell-level metabolism, the regulation of the pH, osmotic pressure and temperature of the whole body, and the protection from microbial and mechanical harm. The hemodynamic response continuously monitors and adjusts to conditions in the body and its environment. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. Hemodynamics or haemodynamics are the dynamics of blood flow.

Blood plasma viscosity