Water Balance

Question 1

Describe ADH

Answer 1

• travels to the kidneys
• causes kidney tubules to become more permeable to water
  = means more water transported from tubules back into blood
  = less urine produced
  = water returns to normal level

Question 2

What releases ADH

Answer 2

Pituitary gland

Question 3

What happens if blood too concentrated

Answer 3

Pituitary gland releases ADH
= causes kidneys to reabsorb more water

Question 4

Describe kidney failure

Answer 4

• when person has kidney failure, their blood contains higher concentration of water, ions and urea than it should

Question 5

Describe kidney dialysis

Answer 5

• patients blood passes over a semi permeable membrane
  = allows urea, ions and water through
• BUT won’t allow larger molecules like to proteins to pass through
• on other side of membrane there’s dialysis fluid
  = contains water and ions but no urea
• urea diffuses from blood into fluid
• fluid constantly refreshed
  = always large concentration gradient for urea
  = conc of water and ions in blood return to normal

Question 6

Disadvantages of kidney dialysis

Answer 6

• patients have to visit hospital several times a week
• must eat controlled diet so they don’t produce too much urea

Question 7

Alternative to kidney dialysis

Answer 7

Kidney transplant

Question 8

Describe kidney transplant

Answer 8

• diseased kidney replaced with healthy kidney from a donor

Question 9

Disadvantages of kidney transplant

Answer 9

• donated kidney may be rejected by patients immune system
• shortage of kidney donors

Question 10

Compare adv and dis of transplant and dialysis

Answer 10

Transplant
- shortage of kidney donors
- allows patient a normal life after
- only expensive initially

Dialysis
- no shortage of dialysis machines
- requires frequent treatments
- expensive in the long term