Chapter 8 part 2: Kidney failure

Question 1

What is kidney failure?

Answer 1

• Kidney failure is the inability of the kidney to function properly, this causes excretory products to accumulate in the blood.

Question 2

What are the causes of kidney failure?

Answer 2

• Kidney failure may be caused by high blood pressure, diabetes, excessive alcohol intake, severe physical damage from accidents, and complication from major surgery (processes).

Question 3

What happens when a kidney fails?

Answer 3

• If a kidney fails, a person can still lead a normal life with the other kidney.

Question 4

What happens if both kidneys fail?

Answer 4

• If a kidney fails, a person can still lead normal life with the other kidney.

Question 5

What happens if both kidneys fail?

Answer 5

• IF both kidneys fail, a person will die, unless he gets a kidney transplant or get treated with dialysis using a dialysis machine (to get all the waste substances out of the body since the kidney cannot do that).

Question 6

How does the dialysis machine stimulate the functions of a kidney?

Answer 6

1. Blood is drawn from the patient’s vein.
2. Blood is then pumped through the partially permeable tubing in the (dialysis) machine.
3. The tubing is then bathed in a specially controlled dialysis fluid.
4. The small molecules (urea, and other metabolic waste products) diffuse out into the dialysis fluid.
   5:
   - Blood cells, platelets and large molecules remain in the tubing.
   - The filtered blood is then returned to a vein in the patient’s arm.

Question 7

What are the 3 features of a dialysis machine?

Answer 7

1. Dialysis fluid:
   Description:
   - Contains the same concentration of essential substances as healthy blood.
   Reason:
   - Ensures that the essential substances sch as glucose, amino acids, and mineral salts do not diffuse out of blood.
   - Enables that the essential substances diffuse into the blood if the patient’s blood is lacking them.
2. Direction of blood flow:
   Description:
   - Does not contain metabolic waste products.
   Reason:
   - Ensures a concnetration gradient for waste products such as urea, excess water, and mineral salts to diffuse out of the tubing.
3. Tubing in the machine:
   Description:
   - Narrow, long, and coiled.
   Reason:
   - Increases surface area-to-volume ratio to speed up the rate of exchange of substances between blood and dialysis fluid.