Answer:
- Not everyone who needs a kidney transplant can have one because there is a limited supply of donor kidneys available.
- Kidneys for transplant can only come from either living donors or deceased individuals who have chosen to donate their organs.
- The demand for kidneys far exceeds the supply, resulting in a long waiting list for transplant candidates.
There are several reasons why the dialysis fluid flows constantly through the machine, which works better than just having stationary fluid.
Firstly, constant flow ensures that fresh dialysis fluid is continuously supplied to the membrane where diffusion takes place. This allows for a more efficient removal of unwanted substances from the blood. If the fluid were stationary, it would quickly become saturated with the unwanted substances and diffusion would slow down.
Secondly, constant flow helps maintain the concentration gradient between the blood and the dialysis fluid. Diffusion occurs from an area of higher concentration to an area of lower concentration. By constantly replenishing the dialysis fluid, a higher concentration of unwanted substances is maintained in the blood, promoting the diffusion process.
Lastly, constant flow helps prevent the formation of blood clots or blockages in the machine. The movement of the dialysis fluid prevents the buildup of substances that could potentially obstruct the flow of blood. Additionally, it helps maintain the integrity of the dialysis membrane, allowing for efficient diffusion.
In summary, not everyone can have a kidney transplant due to the limited availability of donor kidneys. Constant flow of the dialysis fluid in the machine is beneficial because it ensures a fresh supply of fluid, maintains the concentration gradient, and prevents the formation of blood clots or blockages.