3.6 Control of water potential (Kidneys)

Question 1

What happens during ultrafiltration ?

Answer 1

1- Blood from the renal artery (from heart) enters the bowman’s capsule in the kidneys at a very high pressure.
2- This forces smaller molecules being carried by the blood to be forced out down the pressure gradient and this forms the glomerular filtrate.
3- The glomerular filtrate is made up of urea, glucose, salts and water

Question 2

What happens during selective reabsorption ?

Answer 2

1- All glucose in glomerular filtrate must be reabsorbed.
2- Glucose is reabsorbed by co transport of epithelial cells
3- It is carried out by actively transporting sodium ions
4- This creates a low conc gradient of glucose in epithelial cells compared to blood
5- Glucose moves into blood by facilitated diffusion

Question 3

Define homeostasis

Answer 3

The regulation of internal conditions to maintain optimal conditions for enzyme action and cell function