Fluid, Electrolyte and Acid-Base Dynamics

1. Fluid, Electrolyte and Acid-Base Dynamics Human Anatomy and Physiology II Oklahoma City Community College Dennis Anderson

2. Concentration of Solutions • Percent Salt • 0.9% NaCl • Milliosmoles • 300 milliosmoles/Liter • Milliequivalents • 325 milliequivalents/Liter

3. Osmosis

4. Osmosis

5. 0.9% NaCl Hypertonic Solution 3% NaCl

6. Cells Crenate in a Hypertonic Solution

7. 0.9% NaCl Hypotonic Solution 0.5% NaCl

8. Cells in a Hypotonic Solution Swell and May Lyse

9. 0.9% NaCl Isotonic Solution 0.9% NaCl

10. 300 mosm 310 mosm Which Way Will Fluid Move?

11. Application Problem 1 • Michael has recently started working outdoors in the hot weather to earn money for his tuition. After a few days he experienced headaches, low blood pressure and a rapid heart rate. His blood sodium was down to 125 meq/L. The normal is 144 meq/L. How do you explain this?

12. Answer to Problem 1 • Michael lost sodium by perspiration. The low sodium in his blood allowed fluid to move into cells by osmosis. Lack of fluid lowered his blood pressure to give him a headache. The increased heart rate was his bodies way of trying to increase blood pressure.

13. Application Problem 2 • Frank has hypertension. His doctor has advised Frank eat a low salt diet. Frank consumed a lot of salt the day before his last checkup. His blood pressure was up. Why?

14. Answer to Problem 2 • The extra salt Frank ate made his blood hypertonic. Hypertonic blood will attract fluids from body cells by osmosis.

15. Electrolyte vrs. Nonelectrolyte NaCl Na+ + Cl- Glucose Glucose

16. Aldosterone • Hormone secreted from the adrenal cortex • Stimulates kidneys • Retain sodium • Retain water • Secrete potassium

17. Estrogen • Female hormone from the ovaries • Similar to aldosterone • Stimulates the kidneys to retain sodium • Increases fluid retention

18. Cortisol • Hormone from the adrenal cortex • Converts lipids and protein to glucose • Depress inflammation • Stimulates the kidneys to retain sodium • Increases fluid retention • Elevated levels cause edema

19. ADH H2O Antidiuretic HormoneADH Collecting Duct Hypertonic Interstitial Fluid Urine

20. Calcitonin Calcium

21. Estrogen Calcium

22. Parathormone Calcium

23. Blood pH = 7.4(7.35-7.45) Blood pH regulated by 1. Kidneys 2. Lungs 3. Buffers in blood

24. H+ Secreted HCO3- Rebsorbed Blood H+ Kidney Nephron Urine HCO3-

25. Kidneys Regulate pH • Excreting excess hydrogen ions, retain bicarbonate • if pH is too low • Retaining hydrogen ions, excrete bicarbonate • if pH is too high

26. Lungs Regulate pH • Breath faster to get rid of excess carbon dioxide if pH is too low • Carbon dioxide forms carbonic acid in the blood • Breath slower to retain carbon dioxide if pH is too high

27. Carbonic Acid Carbon Dioxide and Acid CO2 + H2O H2CO3H++ HCO3-

28. More Carbon Dioxide = More Acid = Lower pH • Breathing slower will retain CO2 , pH will • decrease (more acid) • Breathing faster will eliminate more CO2 pH will • increase (less acid)

29. Blood pH Drops to 7.3How does the body compensate? • Breath faster to get rid of carbon dioxide • eliminates acid

30. Blood pH Increases to 7.45How does the body compensate? • Breath slower to retain more carbon dioxide • retains more acid

31. John is Taking Narcotics for PainThe narcotics have depressed his breathing rate. What will happen to his blood pH? • pH will decrease because he will retain excess carbon dioxide which will increase the amount of acid in the blood

32. Buffers Regulate pH • Chemicals that resist changes in pH • Prevent large pH changes when an acid or base is added

33. Strong Acid • Acid that releases many hydrogen ions • HCl

34. Weak Acid • Acid that releases only a few hydrogen ions • Carbonic Acid

35. H2CO3 + NaCl HCl + NaOH Strong Acid Base Weak Acid Salt Buffers Change Strong Acids to Weak Acids

36. Bicarbonate: Carbonic Acid • 20:1 = pH 7.4 • 21:1 = pH more than 7.4 • 19:1 = pH less than 7.4

37. Acidosis • pH below 7.35 • Depresses the nervous system • coma

38. Alkalosis • pH above 7.45 • Overexcites the nervous system • convulsions

39. Respiratory Acidosis • Any condition that impairs breathing • Carbon dioxide increases in blood • Excess carbon dioxide lowers pH

40. Respiratory Alkalosis • Hyperventilation • Carbon dioxide decreases in blood • Low carbon dioxide raises pH

41. Metabolic Acidosis • Not caused by breathing or carbon dioxide imbalance • Excess acid in blood • Renal disease, Diabetes or Starvation • Deficiency of bicarbonate in blood • Diarrhea

42. Metabolic Alkalosis • Not caused by breathing or carbon dioxide imbalance • Deficiency of acid in the blood • Vomiting, Diuretics • Excess bicarbonate in the blood • Ingesting sodium bicarbonate

43. Sodium • Attracts water into the ECF • Nerve impulse • Muscle contractions

44. Hypernatremia • Excess sodium in the blood • Hypertension • Muscle twitching • Mental confusion • Coma

45. Hyponatremia • Deficiency of sodium in the blood • Hypotension • tachycardia • Muscle weakness

46. Potassium • Attracts water into the ICF • Nerve impulse • Muscle contractions

47. Hyperkalemia • Excess potassium in the blood • Cardiac arrhythmias and cardiac arrest • Elevated T wave • Muscle weakness

48. Hypokalemia • Deficiency of potassium in the blood • Cardiac arrhythmias and cardiac arrest • Flatened T wave • Muscle weakness

49. Calcium • Most in bones and teeth • Blood clotting • Nerve impulse • Muscle contraction

50. Hypercalcemia • Excess calcium in the blood • Kidney stones • Bone pain • Cardiac arrhythmias