osmoregulation

Question 1

what is the role of the loop of henle?

Answer 1

creates a low water potential with high solute concentration in the tissue fluid around the nephron in the medulla region of the kidney

Question 2

describe the urine of mammals due to the loop of henle

Answer 2

more concentrated than their blood (hypertonic to blood)
- water saving

Question 3

define the counter current system

Answer 3

fluid flows in opposite directions in two vessels close to each other

Question 4

how do the 2 limbs of the loop of henle act as a countercurrent multiplier

Answer 4

ascending limb uses ATP to create the conc gradient needed for water to be removed from the descending limb which moves it back into blood

Question 5

what is the advantage of having a counter current flow?

Answer 5

maximises concentration gradient

Question 6

the ascending limb is ….

Answer 6

permeable to mineral ions but not permeable to water

Question 7

how is the water potential of the tissue fluid decreased?

Answer 7

Na+ and Cl- move out of ascending limb into tissue fluid

Question 8

describe the water potential inside the start of the descending limb

Answer 8

high

Question 9

how is the water potential inside the start of the descending limb decreased?

Answer 9

water moves out into tissue fluid

Question 10

define osmoregulation

Answer 10

control of water potential to prevent osmotic issues in cells

Question 11

describe how water is conserved

Answer 11

• low water potential detected by hypothalamus osmoreceptors
• ADH released
• DCT walls and collecting duct become more permeable
• more water is reabsorbed
• less water goes into urine so it is more concentrated

Question 12

describe how water is removed

Answer 12

• high water potential detected by hypothalamus osmoreceptors
• less ADH released
• DCT walls and collecting duct less permeable
• less water reabsorbed
• more water goes into urine so it is more dilute