Which procedure involves the peritoneum acting as the semipermeable membrane?

Peritoneal dialysis is the procedure in question where the peritoneum functions as a semipermeable membrane. During this process, a sterile solution containing water, electrolytes, and osmotically active substances is introduced into the peritoneal cavity through a catheter. The peritoneum, which is the membrane lining the abdominal cavity, allows for the exchange of waste products and excess fluids from the blood while retaining larger proteins and cells, effectively utilizing its semipermeable properties.

The key aspect of peritoneal dialysis is that it allows for the body's waste products to diffuse into the dialysis fluid while simultaneously balancing the composition of the blood without the need for external machines, which is characteristic of hemodialysis. Although other options involve dialysis-related processes, they do not use the peritoneum as the filtering membrane. Therefore, peritoneal dialysis is distinctive for its use of the natural membrane in the body to facilitate the necessary exchanges needed for effective renal replacement therapy.