1. The Kidney

2. Define excretion

3. The kidney
Urea is a waste product.
Excretion is the removal from the body of waste products of metabolism

4. Excretion
Urea is a waste product from the metabolism of amino acids. Each amino acid must be deaminated (lose an amine group).
It is the job of the kidneys to filter and cleanse the bloodstream of molecules like urea and other molecular wates.

5. How do Kidneys work?

6. 11.3.2 Draw and label the structures of the kidney

7. Excretory System filters blood and produces urine.

8. The Kidney Renal artery – takes blood into the kidney
Renal vein – blood drains out of the kidney
Renal pelvis – area where urine collects
Ureter – takes urine to bladder
Renal medulla – surrounds renal pelvis

9. Annotate a diagram of a glomerulus and associated nephron to show the the function of each part.

10. Glomerulus

11. Nephron Kidneys made up of 1.25 million nephrons
Nephron = filtering unit
Capillary bed = glomerulus
Bowman’s capsule = surrounds glomerulus
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule

12. Explain the process of ultrafiltration, including blood pressure, fenestrated blood capillaries and basement membrane

13. The kidney is the blood’s filtration and balancing system

14. Balancing the Blood

15. Nephron

16. Nephron

17. Ultrafiltration – in the renal capsule

18. Explain the process of ultrafiltration. (8 marks)

19. Explain the process of ultrafiltration. (8 marks)

20. 11.3.5 Explain osmoregulation
Osmoregulation is the control of the water balance of the blood, tissue or cytoplasm of a living organism

21. Osmoregulation Depends on:
Total volume of water ingested recently as liquid & in solid foods
Perspiration rate (exercise level & environmental temperature)
Ventilation rate (breathing rate is largely dependent on exercise level

22. Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule, including the roles of microvilli, osmosis and active transport.

23. Selective Reabsorption
Filtrate leaving Bowman’s capsule contain substances body needs
Water, salt ions, glucose
Occurs in the proximal convoluted tubule
Returned to bloodstream in peritubular capillary bed

24. Selective Reabsorption
Walls of the prox. conv. tubule is one cell thick

25. Selective Reabsorption

26. Selective Reabsorption

27. Selective Reabsorption

28. Explain selective reabsorption in the kidney (8 marks)

29. Explain selective reabsorption in the kidney. (8 marks)

30. Explain the roles of the loop of Henle, medulla, collecting duct and ADH in maintaining the water balance of the blood

31. Loop of Henle

32. Loop of Henle

33. Loop of Henle/medulla

34. Collecting ducts

35. ADH = antidiuretic hormone
Collecting Duct

36. Water concentration in the blood

37. Explain osmoregulation in the kidney (8 marks)

38. Explain osmoregulation in the kidney (8 marks)

39. Explain the differences in the concentration of proteins, glucose and urea between blood plasma, glomerular filtrate and urine

40. Tables don’t have to be memorized
Tables don’t have to be memorized Fluids mentioned associated with the following locations.
Glomerular filtrate = fluid (now called filtrate) which enters into the proximal convoluted tubule after the ultrafiltration process within Bowman’s capsule. No reabsorption has occurred.
Blood Plasma = blood that enters the glomerulus originally from the renal artery & no filtering or reabsorption has yet occurred
Urine = fluid which was the filtrate that has now undergone reabsorption & osmoregulation mechanisms & is taken to the bladder

41. Which nutrients are 100% reabsorbed?
Glucose and amino acids
Where does this happen?
selective reabsorption in the proximal convuluted tubule

42. What is filtered, reclaimed and excreted by the kidney?
The concentration of uric acid is 12.5x greater in the urine than in the filtrate or the blood.
How much more concentrated is urea in the urine than in the blood?
Why is such a large proportion of urea and uric acid excreted?
They are very toxic

43. What is filtered, reclaimed and excreted by the kidney?
What percentage of the following are forced into the nephron by ultrafiltration?
urea –
glucose –
inorganic salts -
proteins & macromolecules -
100%
100%
Too large for ultrafiltration
100% 0%
Why the macromolecule result?

44. Are there any other components not processed by ultrafiltration?
Erythrocytes
Lymphocytes
platelets

45. 11.3.9 Explain the presence of glucose in the urine of untreated diabetic patients.

46. Diabetes and the Kidney
Type I : insulin not produced
Liver does not take up glucose from blood
Type II: insulin receptors inactive
- Liver does not take up glucose from blood
Results: Blood sugar concentration remains high

47. In the Kidney

48. Diabetes & the Kidney

49. From your heart to the Toilet