Final answer:
a) Dialysate
The solution used in Peritoneal Dialysis (PD) is called dialysate, and during dialysis, a membrane is permeable to urea and impermeable to red blood cells to allow for waste removal. Isotonic solutions are used intravenously to maintain proper fluid balance in the body. Concentration gradients in dialysis facilitate waste removal from the blood.
Step-by-step explanation:
The solution introduced into the peritoneum during Peritoneal Dialysis (PD) is called dialysate. In the process of dialysis, a semipermeable membrane separates blood from the dialysate. The semipermeable membrane's characteristics are essential; it is permeable to substances that should be removed from the blood, like urea, and impermeable to important components of blood, such as red blood cells. The correct answer to the question is d. urea, red blood cells, meaning the membrane is likely permeable to urea and impermeable to red blood cells.
Additionally, when dehydrated patients need fluids intravenously, they are given saline at a concentration that is isotonic with respect to body fluids. Using isotonic solutions like normal saline or lactated Ringer's is crucial because it ensures that fluids do not cause cells to shrink or swell by osmosis, maintaining the proper fluid balance in the body.
For dialysis specifically, the concentration gradients are manipulated to facilitate the removal of wastes like urea; for instance, the dialysate in the upper component may have a lower solute concentration compared to blood, allowing urea to diffuse down its concentration gradient.