Kidney Dialysis Hemodialysis, a method of removing waste products from the blood
ID: 261945 • Letter: K
Question
Kidney Dialysis Hemodialysis, a method of removing waste products from the blood if the kidneys have failed, uses a tube made of a cellulose membrane that is immersed in a large volume of aqueous solution. Blood is pumped through the tube and is then returned to the patient's vein. The membrane does not allow passage of large protein molecules and cells but does allow small ions, urea, and water to pass through it Assume that a physician wants to decrease the concentration of sodium ion and urea in a patient's blood while maintaining the concentration of potassium ion and chloride ion in the blood. What materials must be dissolved in the aqueous solution in which the dialysis tube is immersed? How must the concentrations of ions in the immersion fluid compare with those in blood? 11.104.Explanation / Answer
Under this special case of hemodialysis, the physician requires to remove excess of sodium and urea from the blood via dialysis. Further, the physician requires not to remove any potassium ion and chloride ion from the blood.
In order to do so, the aqueous solution must have following ionic properties:
Thus, if the aqueous solution is isotonic with respect to some ions, they will not move across the semi-permeable membrane since there would be an altogether lack of concentration gradient with respect to them. On the other hand, only those molecules and ions will move across the membrane who will experience a concentration gradient.
Thus, the aqueous solution must be hypotonic with respect to the blood in relevance to sodium ions and urea while it must be isotonic with respect to the blood in relevance to potassium and chloride ions.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.