RENAL DIALYSIS

1. RENAL DIALYSIS And Hormone Replacement Therapy

2. Dot Point “ Compare the process of renal dialysis with the function of the kidney”

3. What is Renal Dialysis? • People with dysfunctional kidneys are not able to remove wastes such as urea • They have to undergo renal dialysis to regulate their blood

4. The Two Forms Of Dialysis Are: • Haemodialysis: And • Peritoneal Dialysis:

5. Haemodialysis • Occurs outside of the body • The blood is extracted from a vein and passed into a dialyser, which is a bundle of hollow fibres made of a semi-permeable membrane • The dialyser contains a solution of dialysing fluid, which has similar ion concentrations to blood • The dialyser only allows wastes to pass through, and not blood cells and proteins. In this way it is similar to the filtrations stage of the nephron.

6. Haemodialysis • The wastes diffuse into the solution, and it is constantly replaced • The anti-clotting agent, heparin, is also added to prevent clotting • The blood is then returned to the body

8. Peritoneal Dialysis • This occurs in the body • Dialysis solution is introduced into the peritoneal (abdominal) cavity through a catheter • The lining of the peritoneal cavity is a natural semi-permeable membrane and has its own rich blood supply • The wastes diffuse into the solution, which is replaced.

10. “Outline the general use of hormone replacement therapy in people who cannot secrete aldosterone:” • The adrenal gland secretes aldosterone, without which the body would not be able to regulate salt and water concentrations (problems = dehydration etc) • Artificial hormones (e.g. fludrocortisone ) can be used as a treatment for people who cannot secrete aldosterone (due to a damaged adrenal gland; Addison’s disease).