1. Loop of Henle

2. Spec
(c) (i) the structure, mechanisms of action and functions of the mammalian kidney (ii) the dissection, examination and drawing of the external and internal structure of the kidney (iii) the examination and drawing of stained sections to show the histology of nephrons
To include the gross structure and histology of the kidney including the detailed structure of a nephron and its associated blood vessels AND the processes of ultrafiltration, selective reabsorption and the production of urine. PAG1, PAG2

3. Control, Coordination & Homeostasis
Learning Objective:
To Know The Roles of the Loop of Henle & Collecting Duct
Success Criteria:
Explain Reabsorption in the Loop Of Henley & Collecting Ducts

4. Starter WITHOUT looking at your notes:
Sketch the nephron and label on the parts
Include the division between cortex and medulla

5. Roles of the Loop Of Henle & Collecting Duct
Role to decrease the water potential of the medulla, allowing...
Collecting Duct:
To control the volume and concentration of the urine (therefore allowing water to be reabsorbed into the blood)
Affected by A.D.H

6. Loop Of Henle Important Facts:
In the descending limb the water potential of the fluid is decreased by the addition of mineral ions and the removal of water
In the ascending limb the water potential is increased as mineral ions are removed by active transport
Ascending limb is impermeable to water

7. Stage 1
Na+ and Cl- are actively transported out of the ascending limb

8. Stage 2 This raises the Na+ and Cl- concentration in the tissue fluid
(lowering the water potential)

9. Stage 3 Water is drawn out of the descending limb by OSMOSIS………
And Na+ and Cl- diffuse in down a concentration gradient

10. Stage 4
Removing Water from the limb concentrates the Na+ and Cl- in the descending limb…..

11. Stage 5
So as you go down the limb - Na+ and Cl- diffuses out into the medulla
This concentration of the salt in the medulla is called the “Counter-Current Multiplier”
Decrease the water potential in the medulla

12. OVERVIEW

13. Collecting Duct
As the fluid passes into the collecting duct it has high water potential
It then passes through the salty medulla and water is removed from the filtrate until the urine/medulla are isotonic.
This is then affected by A.D.H

14. Group Task
Model the processes which happen in the Loop of Henle and the Collecting duct.
Draw an outline of the nephron onto A3 paper, put a dashed line where the cortex/medulla divide is
Use different colour playdohs for:
Salts (Na and Cl ions)
Water

15. Plenary
PPQs

19. PPQ
See print out

20. Markscheme

21. Markscheme