Kidneys

Question 1

What substances are kept or removed by the kidney

Answer 1

Useful substances like glucose, and the correct concentration of water and ions are re absorbed into the blood
Waste products like urea and excess water or ions are removed from the body in the urine

Question 2

Describe the process of kidney filtration

Answer 2

Blood is brought in to the kidney from the renal artery
All products from the blood are filtered into the kidney via kidney tubules
Selective re absorption determines which products to keep or remove via urine
Waste products go to the bladder

Question 3

How does the body control what quantity of water is reabsorbed

Answer 3

The hormone ADH (anti-diuretic hormone)is responsible for kidney tubule permeability.
It is secreted from the pituitary gland into the blood
If water concentration is too high, less ADH is secreted so the tubules become Les permeable and reabsorb less water
The opposite happens for too little water in the blood

Question 4

What are the two main methods of treating kidney failure and what are their advantages and disadvantages

Answer 4

Dialysis machines involve removing blood from the body and passing it between partially permeable membranes in the dialysis machine which adds and removes the correct amount of substances in the blood

Advantages- no need for transplant
Disadvantages- time consuming, risk of contamination, not permenant, expensive

Transplants involve getting a kidney from a donor with the same blood time and genetics as you ( often a family member) to replace the faulty ones

Advantages- permanent fix
Disadvantage- risk of rejection or complications in surgery, surgery can be expensive

Question 5

Give 2 examples of what is contained in Urea

Example of an Ion

Answer 5

1. Proteins (and amino acids they are broken down into) _ any excess amino acids are converted to fats and carbohydrates which are stored in liver (called deamination)
2. Ammonia -waste product (toxic) so converted to urea in liver

Sodium example of Ion