In peritoneal dialysis, the diffusion and osmosis that move substances between blood and dialysate occur across which membrane?

In peritoneal dialysis, the diffusion and osmosis that move substances between blood and dialysate occur across which membrane?

• A. Across the alveolar membrane
• B. Across the peritoneal membrane
• C. Across the skin
• D. Across the gastrointestinal mucosa

Answer: (B)

In peritoneal dialysis, diffusion and osmosis occur across the peritoneal membrane. This thin, semi-permeable lining of the abdominal cavity has a rich capillary network, so small solutes move from blood into the dialysate by diffusion, while water moves by osmosis driven by the osmotic gradient created by the dialysate solution (often glucose). This membrane is the barrier that enables exchange between the blood and the dialysate. The alveolar membrane handles gas exchange in the lungs, not dialysis; the skin and gastrointestinal mucosa are not involved in this process.

In peritoneal dialysis, diffusion and osmosis occur across the peritoneal membrane. This thin, semi-permeable lining of the abdominal cavity has a rich capillary network, so small solutes move from blood into the dialysate by diffusion, while water moves by osmosis driven by the osmotic gradient created by the dialysate solution (often glucose). This membrane is the barrier that enables exchange between the blood and the dialysate. The alveolar membrane handles gas exchange in the lungs, not dialysis; the skin and gastrointestinal mucosa are not involved in this process.