In peritoneal dialysis, excess fluid and waste products are removed by which mechanisms?

In peritoneal dialysis, excess fluid and waste products are removed by which mechanisms?

• A. Osmosis and diffusion
• B. Active transport; Endocytosis
• C. Diffusion only
• D. Filtration only

Answer: (A)

In peritoneal dialysis, waste products move from blood into the dialysate by diffusion, which is movement down a concentration gradient across the semi-permeable peritoneal membrane. At the same time, excess fluid is removed mainly through osmosis, driven by the osmotic gradient created by the dialysis solution (typically glucose), pulling water from the blood into the dialysate. Active transport or endocytosis aren’t involved in this process, since they require energy and are not how PD clears wastes or removes fluid. Filtration isn’t the primary mechanism here; the combined action of diffusion for solutes and osmosis for water best explains how PD works.

In peritoneal dialysis, waste products move from blood into the dialysate by diffusion, which is movement down a concentration gradient across the semi-permeable peritoneal membrane. At the same time, excess fluid is removed mainly through osmosis, driven by the osmotic gradient created by the dialysis solution (typically glucose), pulling water from the blood into the dialysate. Active transport or endocytosis aren’t involved in this process, since they require energy and are not how PD clears wastes or removes fluid. Filtration isn’t the primary mechanism here; the combined action of diffusion for solutes and osmosis for water best explains how PD works.