2. Water And The Major Minerals Copyright 2005 Wadsworth Group, a division of Thomson Learning

3. Water And The Body Fluids Functions of water: –Transport –Structural support for molecules –Participates in metabolic reactions –Solvent –Lubricant –Body temperature regulation –Maintains blood volume Copyright 2005 Wadsworth Group, a division of Thomson Learning

4. Water And The Body Fluids Water balance and recommended intakes –Intracellular fluid –Extracellular fluid Interstitial fluid Copyright 2005 Wadsworth Group, a division of Thomson Learning

5. One Cell And Its Associated Fluids Copyright 2005 Wadsworth Group, a division of Thomson Learning

6. Water And The Body Fluids Water balance and recommended intakes –Water intake Thirst Dehydration Water intoxication Copyright 2005 Wadsworth Group, a division of Thomson Learning

8. Water And The Body Fluids Water balance and recommended intakes –Water sources –Even water sources with caffeine Copyright 2005 Wadsworth Group, a division of Thomson Learning

9. Water Sources, Losses and Recommendations A camel can go for some time without water because it generates metabolic water by respiration of the fat in its hump but only for a short time. It will drink water as soon as it can. For humans metabolic water is not enough for maintaining fluid balance even for a short time You can get water from foods but then you will also get a lot of calories So we have to get our water from liquids ideally just plain water Other loss methods – vomitting or diarrhea

11. Health Effects of water Water balance and recommended intakes –Water recommendations Based on diet, activity, environmental temperature, body temperature, humidity For a person who expends 2000 kcalories per day –2 to 3 liters of water i.e. about 7 to 11 cups –Health effects of water Hard water –Calcium, Magnesium –Better for drinking if you have heart disease or hypertension Soft water –Sodium or Potassium –Better for household use (Lathering) Bottled water More on Water in Chapter 13

12. Copyright 2005 Wadsworth Group, a division of Thomson Learning

13. Blood Volume and Blood Pressure ADH (Antidiuretic hormone) and Water retention Renin and Sodium retention Angiotensin and Blood vessel constriction Aldosterone and sodium retention

14. Too little water Too little water in the blood, detected by the hypothalamus. More ADH produced by the pituitary gland. More water reabsorbed by the kidneys, caused by ADH. Blood becomes less concentrated. Negative feedback; hypothalamus detects change in blood concentration. Pituitary produces less ADH. Blood returns to correct osmotic concentration.

15. Too much water Too much water in the blood, detected by the hypothalamus. Less ADH produced by the pituitary gland. Less water reabsorbed by the kidneys, caused by ADH. Blood becomes more concentrated. Negative feedback; hypothalamus detects change in blood concentration. Pituitary produces more ADH. Blood returns to correct osmotic concentration.

16. Copyright 2005 Wadsworth Group, a division of Thomson Learning How The Body Regulates Blood Volume and therefore blood pressure

17. Fluid And Electrolyte Balance Dissociation of salt in water –Ions Cations – positively charged Anions – negatively charged –Electrolyte solution Pure water is a poor conductor of electricity But ions dissolved in water will conduct electricity Hence salts dissolved in water are called electrolytes Copyright 2005 Wadsworth Group, a division of Thomson Learning

18. Fluid And Electrolyte Balance Electrolytes attract water –Water has weak positive and negative charges Water follows electrolytes –Solutes –Osmosis –Osmotic pressure Copyright 2005 Wadsworth Group, a division of Thomson Learning

19. Water Dissolves Salts And Follows Electrolytes

20. Fluid And Electrolyte Balance Electrolytes that are predominantly inside cells –Potassium, Magnesium, Phosphate and Sulfate Electrolytes that are predominantly outside cells –Sodium and Chloride Cell membrane are selectively permeable Water follows electrolytes –Solutes –Osmosis –Osmotic pressure Copyright 2005 Wadsworth Group, a division of Thomson Learning

21. Fluid And Electrolyte Balance Water follows electrolytes –Solutes Salts, proteins etc that are dissolved in water or fluid –Osmosis Movement of water from areas of lower concentration of solutes to areas of higher concentration of solutes –Osmotic pressure Amount of pressure needed to prevent osmosis across a membrane Copyright 2005 Wadsworth Group, a division of Thomson Learning

23. Vegetables “sweat” when sprinkled with salt Raisins plump up when immersed in water

25. Fluid And Electrolyte Balance Proteins regulate flow of fluids and ions –Edema –Transport proteins e.g. Sodium Potassium pumps (remove sodium actively from the cell) Regulation of fluid and electrolyte balance happens by controlling –The amount of minerals absorbed or reabsorbed in the GI tract –The amount of minerals excreted or reabsorbed by the kidneys Copyright 2005 Wadsworth Group, a division of Thomson Learning

26. Sodium and chloride most easily lost –Sweating, bleeding, excretion Different solutes lost by different routes –Vomiting or diarrhea: Sodium –Aldosterone over production (tumor): Potassium (from kidneys) –Uncontrolled diabetes: Glucose –With serious losses like this medical intervention is necessary Copyright 2005 Wadsworth Group, a division of Thomson Learning Fluid And Electrolyte Balance

27. Fluid And Electrolyte Imbalance Replacing lost fluids and electrolytes –Oral rehydration therapy (ORT) Copyright 2005 Wadsworth Group, a division of Thomson Learning

28. Acid- Base Balance pH

29. Acid-Base Balance Remember that a buffer is a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. Regulation by the buffers in body fluids –Bicarbonate (Base) –Carbonic acid (Weak Acid) –Some proteins (Remember proteins can act as both base and acid) Copyright 2005 Wadsworth Group, a division of Thomson Learning

30. Acid-Base Balance Regulation by the lungs –CO2 formed by cells during respiration dissolves in blood to form carbonic acid which dissociated to form H+ and bicarbonate –Too much acid ->respiration speeds up -> more CO2 is exhaled –Too much bicarbonate -> respiration slows down -> increases the amount of dissolved CO2 i.e. carbonic acid Copyright 2005 Wadsworth Group, a division of Thomson Learning

31. Acid-Base Balance Regulation by the kidneys –The kidneys have two important roles in the maintaining of the acid-base balance: reabsorb bicarbonate from urine excrete hydrogen ions into urine –The acidity of urine changes to ensure that the body’s total acid-base balance stays the same. Copyright 2005 Wadsworth Group, a division of Thomson Learning

32. The Minerals - An Overview

33. Inorganic elements –Not easily destroyed or modified –Can only be lost by leaching into water The body’s handling of minerals –Minerals like Potassium easily absorbed –Minerals like Calcium act more like fat soluble vitamins and need carriers Variable bioavailability –Binders (combine with minerals preventing or reducing absorption) Phytates (e.g. in Legumes and grains) Oxalates (e.g. in rhubarb and spinach) Copyright 2005 Wadsworth Group, a division of Thomson Learning

34. The Minerals - An Overview Nutrient interactions –Similar to the interactions of Vitamins Varied roles –Fluid balance – Sodium, Chloride and Potassium –Bone growth and health – Calcium, Phosphorous and Magnesium Copyright 2005 Wadsworth Group, a division of Thomson Learning

35. Sodium Roles in the body –Principal extracellular cation –Regulates extracellular volume –Assists in nerve impulse transmission and muscle contraction You never really need to add Sodium to food (there is always enough in foods naturally) The kidneys remove all the Sodium and only return what is needed to the blood When there is too much Sodium in the body, thirst is induced to increase water intake Copyright 2005 Wadsworth Group, a division of Thomson Learning

36. Sodium Hypertension –Salt sensitivity People whose parents have high blood pressure People with kidney disease or diabetes African Americans People over 50 Osteoporosis –High Sodium intake -> loss of calcium –Effects on Bone density is unknown –Reducing Sodium causes no harm but may be good Foods –Natural foods are good in two ways They have low Sodium They have high Potasium Both of which are associated with better blood pressure regulation Copyright 2005 Wadsworth Group, a division of Thomson Learning

37. Sodium Copyright 2005 Wadsworth Group, a division of Thomson Learning More Sodium in ½ cup instant chocolate pudding than in 1 ounce of salted peanuts

38. Sodium Deficiency symptoms –Muscle cramps, mental apathy, loss of appetite Toxicity symptoms –Edema, acute hypertension Significant source –Table salt, soy sauce –Moderate amounts in meats, milks, breads, and vegetables –Large amounts in processed foods Copyright 2005 Wadsworth Group, a division of Thomson Learning

39. Chloride Chlorine (Cl 2 ) vs. chloride ion (Cl - ) Roles in body –Principal extracellular anion –Maintains normal fluid and electrolyte balance –Part of hydrochloric acid found in the stomach, necessary for proper digestion Copyright 2005 Wadsworth Group, a division of Thomson Learning

40. Chloride: In Summary Deficiency symptoms –Do not occur under normal circumstances Toxicity symptom –Vomiting Significant sources –Table salt, soy sauce –Moderate amounts in meats, milks, eggs –Large amounts in processed foods Copyright 2005 Wadsworth Group, a division of Thomson Learning

41. Potassium Roles in body –Principal intracellular cation –Maintains normal fluid and electrolyte balance –Facilitates many reactions –Supports cell integrity –Assists in nerve impulse transmission and muscle contractions Copyright 2005 Wadsworth Group, a division of Thomson Learning

42. Potassium: In Summary Deficiency symptoms –Muscular weakness –Paralysis –Confusion Toxicity symptoms –Muscular weakness –Vomiting –If given into a vein, can stop the heart Copyright 2005 Wadsworth Group, a division of Thomson Learning

43. Potassium: In Summary Significant sources –All whole foods –Meats, milks, fruits, vegetables, grains, legumes Copyright 2005 Wadsworth Group, a division of Thomson Learning

45. Phosphorus Chief functions in the body –Mineralization of bones and teeth –Part of every cell –Important in genetic material, part of phospholipids –Used in energy transfer and in buffer systems that maintain acid-base balance Copyright 2005 Wadsworth Group, a division of Thomson Learning

46. Phosphorus Deficiency symptoms –Muscular weakness, bone pain Toxicity symptoms –Calcification of nonskeletal tissues, particularly the kidneys Significant sources –All animal tissues (meat, fish, poultry, eggs, milk) Copyright 2005 Wadsworth Group, a division of Thomson Learning

48. Magnesium Chief functions in the body –Bone mineralization, building of protein, enzyme action, normal muscle contraction, nerve impulse transmission, maintenance of teeth, and functioning of immune system Copyright 2005 Wadsworth Group, a division of Thomson Learning

49. Magnesium Deficiency symptoms –Weakness –Confusion –If extreme, convulsions, bizarre muscle movements (especially of eye and face muscles), hallucinations, and difficulty in swallowing –In children, growth failure Copyright 2005 Wadsworth Group, a division of Thomson Learning

50. Magnesium Toxicity symptoms –From nonfood sources only –Diarrhea, alkalosis, dehydration Significant sources –Nuts, legumes –Whole grains –Dark green vegetables –Seafood –Chocolate, cocoa Copyright 2005 Wadsworth Group, a division of Thomson Learning

52. Sulfur Roles –Not used as a nutrient –Present in amino acids Cysteine and Methionine –In B Vitamin, Thiamin –No deficiencies are known Copyright 2005 Wadsworth Group, a division of Thomson Learning

53. Calcium And Osteoporosis Will be done with Chapter 13 Copyright 2005 Wadsworth Group, a division of Thomson Learning