Electrolyte balance regulator

Body fluids are generally divided into intracellular fluids and extracellular fluids by cell membranes. The extracellular fluids are divided into plasma and intercellular fluids by capillary blood vessels. The total body fluid of normal adults accounts for about 60% of body weight, of which 40% is intracellular fluid, 5% is plasma, and 15% is intercellular fluid. Solutes in body fluids can be divided into electrolytes and non-electrolytes. Non-electrolytes include glucose and urea, and the electrolytes mainly include cations such as Na+, K+, Ca2+, and Mg2+, and anions such as Cl-, HCO3-, and HPO42-. There is a significant difference in the distribution of electrolytes inside and outside the cell. The extracellular fluid is represented by plasma, in which the main cation is Na+, the anion is Cl-, followed by HCO3-, the cation of the intracellular fluid is mainly K+, followed by Mg2+, and the anion is With HPO42- and protein as the mainstay, Na+-K+ATPase on the cell membrane can continuously pump Na+ out of the cell, while pumping K+ into the cell while providing energy by ATP. Na+ can reach equilibrium within and outside the cell 1 hour after entering the body fluid, and the time to reach equilibrium in the whole body is 24 hours; while K+ takes 15 hours to reach equilibrium inside and outside the cell, and the balance time of the patient is prolonged: such as heart disease patients It takes 45 hours to reach equilibrium. In addition, K+ enters the cell with the synthesis of glycogen and protein, and vice versa. Therefore, the blood potassium level measured once in the clinic cannot accurately reflect the current content in the body. Potassium recovers slowly in cells. It usually takes 4-6 days to reach equilibrium. In severe cases, it takes 10-20 days or even longer to correct the potassium deficiency in the cells. Therefore, it is necessary to follow the slow, rare and less potassium supplementation. in principle. The main factor determining the distribution of water between body fluids is the osmotic pressure of body fluids. Osmotic pressure is the attraction of solute particles such as electrolytes and non-electrolytes to water in solution. The osmotic pressure of normal plasma and cells is approximately equal, 280-320mmol/L. Any solution with equal osmotic pressure and plasma osmotic pressure is called isotonic solution. Below or above this level, it is called hypotonic or hypertonic. Solution. Moisture can move from hypotonic to hypertonic through the cell membrane. The disorder of water and electrolyte first affects the osmotic pressure and volume of the extracellular fluid. Therefore, the clinical osmotic pressure and volume change are changed according to the concentration of blood sodium. For example, isotonic water loss (dehydration) is the loss of sodium in proportion to water; hypotonic water loss is more than sodium loss; high permeability water loss is more water loss than sodium loss.