The factors that maintain the normal morphology of red blood cells and regulate the water balance inside and outside cells are () A. Plasma colloid osmotic pressure B. Tissue fluid colloid osmotic pressure C. Plasma. A, plasma colloid osmotic pressure is the osmotic pressure formed by protein in plasma, including albumin, globulin and fibrinogen, of which albumin is the most important. Colloid osmotic pressure plays an important role in maintaining water balance inside and outside blood vessels. B interstitial fluid colloid osmotic pressure: the fluid oozing from the arterial end of capillary, which is produced by protein.

C. The osmotic pressure formed by small molecular crystal substances such as electrolyte, glucose and urea in plasma is called crystal osmotic pressure, and 80% of small molecular substances come from sodium ions and chloride ions. Due to the small molecular weight of crystalline substances and the large number of solute particles, the osmotic pressure of crystals accounts for about 99.6% of the total osmotic pressure of plasma. The osmotic pressure of lens can change the liquid balance inside and outside the cell.

D. Hydrostatic pressure of interstitial fluid means that the interstitial fluid itself is squeezed by the surrounding forces in a static state. In order to maintain its relative static state, there must be an equal amount of reaction force to offset the squeezing pressure, which is called hydrostatic pressure.

E, plasma albumin exists in globular protein with high water solubility in plasma, and can be prepared into a solution with a concentration of 30%; Also known as serum albumin, it accounts for 50 ~ 60% of the total protein content in blood and has a molecular weight of 66,000. Lipids that do not contain sugar, but often contain long-chain fatty acids, can be produced by ammonium sulfate precipitation or ethanol precipitation.

So choose: C.