1.  Adam, Amy, Karl, Karlene, and Yifan

2. Introduction  http://www.youtube.com/watch?v=guOqyi5lUQQ (1:46-4:36) http://www.youtube.com/watch?v=guOqyi5lUQQ  Regulates bodily fluids, excreting and recycling waste  Main organs: kidneys, ureters, bladder and urethra  Disorders of the excretory system

3. Excretion  After metabolic activities (energy release, maintenance, repair) results in waste  Separating the needed and the unneeded or no longer needed  Skin, respiratory system, digestive system, excretory system

4. Major functions of excretory system Excretion of waste Maintenance of water and salt pH control Secretion of hormones Overall Major Functions

5. Functions: Excretion of Metabolic Waste  The average person urinates 3000 a year  Bladder can hold 16-24 ounces of urine  Nitrogenous waste  Urea makes up the majority of this waste

6. Functions: Maintenance of Water-Salt Balance  Maintain balance with water and salt in blood  Regulating blood pressure  Balance between potassium, bicarbonate and calcium  Cells need to stay in an isotonic solution

7. Functions: Maintenance of Acid-Base Balance  Buffer for blood  Blood pH: 7.4  Urine is usually a pH of 6  Maintenance of alkaline reserve

8. Functions: Secretion of Hormones  Aids endocrine system in hormonal secretion  Calcitriol: Promotes calcium absorption  Erythropoiten: Production of red blood cells  Renin

9. Major Organs Kidney (Nephrons) Ureter Urinary bladder Urethra

10. Organs  Kidneys: Lower back, filters waste from blood, functions named above  Ureter: Muscular tubes that carry urine  Urinary Bladder: Urine is stored  Urethra: Tube that urine is secreted from

12. Kidney: Introduction

13. Kidney: Pathway Nephron

14. Kidney: Pathway  Filter  Tubule  Duct

15. Kidney: Filter  Renal artery enters Bowman’s capsule; glomerulus  Walls of glomerulus are impermeable to large molecules  pressurized blood aids filtration  Small molecules are permeable  The result is known as filtrate

16. Kidney: Tubule  Bowman’s capsule is connected to a looped tubule  Divided into three parts  Proximal convoluted tubule  Loop of Henle  Distal convoluted tubule  Used by each nephron for reabsorption

17. Kidney: Tubule  Proximal convoluted tubule  Uses ATP for active transport  Drives sodium ions, glucose, and other solutes back into the blood  Water follows these substances into the blood by osmosis

18. Kidney: Tubule  Loop of Henle

19. Kidney: Tubule  Loop of Henle  Descending limb extends from within the renal cortex into the renal medulla; extremely salty  Permeable to water; water flows back into blood  Ascending limb is impermeable to water and slightly permeable to solutes  Na + diffuses out of the tubule and into nearby blood vessels

20. Kidney: Tubule  In the thick-walled section, more Na + is removed by active transport (uses ATP)  Replenishes medulla’s salt  Makes the filtrate less concentrated than surrounding cortex tissue

21. Kidney: Tubule 1.Medulla is salty 2.Reabsorption of water causes salt concentration to decrease 3.ATP is used to actively reabsorb sodium ions 4.Increases osmolarity for future filtrate

22. Kidney: Tubule  Loop of Henle

23. Kidney: Tubule  Distal convoluted tubule  Active reabsorption depends on the needs of the body (sodium ions)  Passive reabsorption of negative ions occurs by electrical attraction (chloride)  Potassium ions and hydrogen ions are actively secreted by the body

24. Kidney: Duct  Tubule empties into a large pipe-like channel called a collecting duct  Lowers back into the medulla; reabsorbs water  The size of the pores depends on signals from the brain  The result can now be called urine  Reabsorbed substances are returned to the body

25.  The roles of ADH and aldosterone in regulating water balance

26. Water Balance: Pituitary Gland  The pituitary gland is a gland at the base of the brain that sends signals to other glands and organs such as the thyroid gland, adrenal glands, ovaries, and testes  Directs them to produce certain hormones  Produces LD, ADH, FSH, and growth hormones

27. Water Balance: The Brain

28. Water Balance: Aldosterone  Aldosterone is a hormone that is produced by the adrenal glands  It works primarily on kidney (renal) cells to help maintain the balance of fluids and electrolytes in our bodies  It mainly works to control reabsorption of sodium and chloride and secretion of potassium and hydrogen

29. Water Balance: Aldosterone  Pathway:  The role of aldosterone in sodium and water balance is to regulate fluid and electrolyte balance  When sodium and plasma volume is decreased, it triggers the synthesis and secretion of aldosterone  When sodium and plasma volume return to normal levels, aldosterone secretion is reduced

30. Water Balance: Adrenal Gland

31. Water Balance: ADH  A hormone produced in the hypothalamus and secreted by the posterior pituitary gland  ADH stimulates reabsorption of water through the distal tubules and collecting ducts of the kidney, resulting in less water being excreted in the urine, thus conserving water

32. Water Balance: ADH  Pathway:  Part of the brain, the hypothalamus, detects that there is not enough water in the blood. The hypothalamus sends a message to the pituitary gland, which releases ADH. ADH travels from brain to the kidney and causes the kidneys to absorb more water and concentrate the urine. A lack of ADH results in increased urine volume and increased urination, a condition called diabetes insipidis.

33. Water Balance: ADH  ADH: antidiuretic hormone  Pathway:  Part of the brain, the hypothalamus, detects that there is not enough water in the blood  The hypothalamus sends a message to the pituitary gland, which releases ADH  ADH travels from brain to the kidney and causes the kidneys to absorb more water and concentrate the urine  A lack of ADH results in increased urine volume and increased urination, a condition called diabetes insipidis.

34. Water Balance: Deficit

35. Water Balance: Surplus

36. Water Balance: End of Cycle

37.  Regulation of Blood pH Maintaining Blood pH in the Excretory System

38. Blood pH: Introduction  The normal pH of blood is around 7.4  Allows our enzymes to function optimally  Failing to maintain homeostasis causes our blood pH to either increase or decrease  This increase/decrease can result in serious medical condition

39. Blood pH: Introduction  One way our blood pH can change in based on the foods/liquids we consume  Blood pH can also changed from metabolic processes  Three main homeostatic mechanisms used to maintain blood pH  Acid-Base Buffer System  Respiratory Centre  Kidney Function

40. Blood pH: Acid-Base Buffer  Buffers blood; prevents changes in pH  Takes up extra H + ions of extra OH - ions that enter the blood  One of the most important buffer system involves the use of carbonic acid and bicarbonate ions

41. Blood pH: Acid-Base Buffer  The system reacts differently depending on the presence of extra hydrogen ions of extra hydroxide ions  If H + is added, the reaction that occurs is:  H + + HCO 3 -  H 2 C0 3  When OH - ions are added to blood:  OH - + H 2 CO 3  HCO 3 - + H 2 O

42. Blood pH: Acid-Base Buffer  In the first reaction, the bicarbonate ion takes up excess hydrogen ion, in order to form carbonic acid  In the second reaction, water is produced  Water will help maintain the blood pH, since water is neutral  These reactions temporarily prevent major changes in pH

43. Blood pH: Respiratory Centre  The hydrogen ion concentration is raised, the respiratory centre (in the medulla oblongata) increases breathing rate  It does this through specific signals that ensure our breathing muscles contract and relax regularly  Doing this causes the body to get rid of hydrogen ions  H + + HCO 3 -  H 2 CO 3  H 2 O + CO 2

44. Blood pH: Respiratory Centre  When the reaction moves from carbon dioxide to hydrogen, the blood pH decreases and increases the other way  Increasing breathing causes carbon dioxide to be generated more quickly, decreasing the number of hydrogen ions  It is vital to have the correct proportion of carbonic acid to bicarbonate ions in blood  Breathing causes a readjustment so the proportion is correct so H + and OH - can continue to be absorbed

45. Blood pH: Kidneys  The first two mechanisms are aided by powerful actions of the kidneys  Only the kidneys are able to rid the body of a vast range of acidic and basic substances  Kidneys are slower acting, but have a more powerful effect  It is possible to urinate the excess acidic H + ions or basic HCO 3 - ions in order to raise or lower blood pH

46. Blood pH: Kidneys  Imagine the kidneys as releasing H + and reabsorbing HCO 3 - in order to maintain homeostasis  If blood is too acidic, H + is released and HCO 3 - is absorbed  However, if blood is basic, neither is used  Another way of buffering is by using ammonia  Removes hydrogen ions and adds in bicarbonate ions  NH 3 + H +  NH 4 +

47. Blood pH: Kidneys  Ammonia is produced in the tubule cells through the breakdown of amino acids  Ammonia works to produce ammonium ions  For every ammonium ion that is produced, a new HCO 3 − is made

48. Blood pH: Summary  There are three mechanisms used to maintain homeostasis, in terms of blood pH  Acid-Base Buffer System  Respiratory Centre  Kidney Function  Each one has a unique way of doing so  All three have advantages and disadvantages that go along with them

49. Dialysis: Introduction  What is dialysis?  Procedure that removes wastes and excess fluid from the blood when kidney function is lost due to renal failure  Why is dialysis needed?  Hyperkalemia  High potassium  Hyperphosphatemia  High phosphate  Uremia  Edema

50. Dialysis: Two Types

51. Conclusion  The human excretory system is responsible for removing liquid waste from the body  The excretory system also regulates the acid-base balance and water-salt balance of the blood and secretes some hormones like ADH  The kidneys are composed of millions of functional units called nephrons that filter the waste from the blood and produce urine.  Dialysis is the procedure that removes wastes and excess fluid from the blood when kidney function is loss due to renal failure

52. Question #1  What is urine?

53. Answer  Filtrate of the nephron upon leaving the collecting duct; exits the body through the urethra

54. Question #2  What is a function in the excretory system that is involved in regulating blood pressure and the appropriate potassium, bicarbonate, and calcium levels in blood?

55. Answer

56. Question #3  What is the role of ADH?

57. Answer  Stimulates reabsorption of water through the distal tubules and collecting ducts of the kidney  Results in less water being excreted in urine

58. Question #4  What is the pituitary gland?

59. Answer  Gland at the base of the brain  Send signals to other glands and organs to produce certain hormones

60. Question #5  What is this picture showing?

61. Answer  Respiratory Centre Equation

62. Question #6  What is this picture showing?

63. Answer  The process of how the kidneys maintain the pH of blood

64. Question #7  Name the 2 types of dialysis. What are their differences?

65. Answer  Hemodialysis  Removing wastes and excess fluids from the blood by an external devices connected to an artery and a vein in a person’s arm.  For acute renal failure  Peritoneal Dialysis  Removing wastes and excess fluids from the blood by inserting a catheter into the abdominal cavity.  For Chronic renal Failure

66. Question #8  What type of dialysis is this picture showing?

67. Answer  Hemodialysis

68. References  http://www.nhlbi.nih.gov/health//dci/Diseases/hlw/hlw_ controls.html http://www.nhlbi.nih.gov/health//dci/Diseases/hlw/hlw_ controls.html  http://h2g2.com/approved_entry/A8819652 http://h2g2.com/approved_entry/A8819652  https://www.inkling.com/read/textbook-of-medical- physiology-guyton-hall-12th/chapter-30/combination-of- excess-h-with https://www.inkling.com/read/textbook-of-medical- physiology-guyton-hall-12th/chapter-30/combination-of- excess-h-with  Grade 12 Biology Textbook

69.  Carter-Edwards, T., Gerards, S., Gibbons, K., McCallum, S., Noble, R., Parrington, J.,...Whyte-Smith, A. (2011). Biology 12. Canada, McGraw-Hill Ryerson, pp.444-462.  DeBruyne, L. K., Pinna, K., & Whitney, E. (2012). Nutrition & Diet Therapy (8 th ed.). United States, Wadsworth, Cengage Learning, pp595-607.

70.  http://www.youtube.com/watch?v=cc8sUv2SuaY http://www.youtube.com/watch?v=cc8sUv2SuaY  http://www.youtube.com/watch?v=WtrYotjYvtU http://www.youtube.com/watch?v=WtrYotjYvtU  http://www.webmd.com/a-to-z-guides/function-kidneys http://www.webmd.com/a-to-z-guides/function-kidneys  http://science.howstuffworks.com/life/human- biology/kidney1.htm http://science.howstuffworks.com/life/human- biology/kidney1.htm