Water and Electrolytes (Chapter 11) PDF

CHAPTER 11 Water and the Electrolytes 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a pub...

CHAPTER 11 Water and the Electrolytes 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Water and the Body Fluids About 60% of body weight (higher in children) Dependent on body composition ¾ of weight in lean tissue is water < ¼ of weight in fat tissue Proportion of water is lower in: Females Obese individuals Elderly 2 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Water and the Body Fluids Functions: Carries nutrients and waste products Maintains the structure of large molecules Participates in metabolic reactions Serves as a solvent Acts as a lubricant Aids in body temperature regulation Maintains blood volume 3 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Water and the Body Fluids Distribution and Movement of Body Fluids Every cell contains fluid and is surrounded by fluid. Intracellular Extracellular (interstitial) Continual turnover. Rapid adjustments to maintain homeostasis. Homeostasis = the maintenance of constant internal conditions. E.g. blood chemistry, temperature, etc 4 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or rd posted to a publicly accessible website, in whole or in part. Osmosis Carla D’Andreamatteo, MSc, RD. Understanding Nutrition, 3 rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Water Follows Electrolytes Some electrolytes reside inside the cell P, K, Mg, S Some electrolytes reside outside the cell Na, Cl Water follows electrolytes across the cell membrane Osmosis Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Fluid and Electrolyte Balance Proteins regulate fluid movement Attract water Transport proteins Passage of ions across cell membranes Sodium-potassium pump Regulation of fluid and electrolyte balance GI tract Kidneys Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.  Blood Volume and Blood Pressure Fluids maintain blood volume, which influences blood pressure. What happens when blood volume and/or blood pressure decrease: Antidiuretic hormone (ADH): Released by the pituitary gland. Is a water conserving hormone that tells kidneys to retain more water. Also triggers thirst. Renin: Released by kidney cells. Tells the kidneys to reabsorb more sodium. Water follows sodium. Also hydrolyzes Angiotensin I in the liver. Angiotensin II: A vasoconstrictor converted from Angiotensin I. Increases blood pressure. Tells the adrenal glands to release aldosterone. Aldosterone: Tells the kidney to retain sodium and excrete potassium. Again, water follows sodium. Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Blood Volume and Blood Pressure Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Water and the Body Fluids Acid–Base Balance 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, 0or posted to a publicly accessible website, in whole or in part.  Acid–Base Balance Acidity in body fluids determined by concentration of H+ ions produced during metabolism (remember the electron transport chain). Need to be neutralized to protect against pH fluctuations: buffers in blood, respiration in lungs, excretion by kidneys. Blood: Lungs: Kidneys: Contains CO2 Reabsorb or proteins, Respiration excrete bicarbonate, rate bicarbonate and carbonic acid = buffers Controlled by lungs and kidneys Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Water and the Body Fluids Distribution and Movement of Body Fluids Water Intake Controlled by hypothalamus ↓ water = concentrated blood = ↑ thirst ↑ water = distension of stomach = ↓ thirst Dehydration Thirst, weakness, exhaustion, delirium Water intoxication Confusion, convulsions, death, hyponatremia 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,2or posted to a publicly accessible website, in whole or in part. Water and the Body Fluids Water Recommendation 1.0 to 1.5 mL/kcal expended (adults) 1.5 mL/kcal expended (infants and athletes) AI for Total Water Men: 3.7 L/day Women: 2.7 L/day 1 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, 3or rd posted to a publicly accessible website, in whole or in part. Sodium Table salt = sodium chloride (NaCl) Preserves food and enhances taste Roles in the body: Fluid balance Acid–base balance Nerve transmission Muscle contraction Readily absorbed and travels freely in the blood to the kidneys 1 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,4or rd posted to a publicly accessible website, in whole or in part. Sodium AI for sodium 1500 mg/day (19–50 yr) 1300 mg/day (51–70 yr) 1200 mg/day (70 yr) CDRR for sodium 2300 mg/day *Additional DRI, based on intakes that result in the reduction of chronic disease risk. 1 5 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or rd posted to a publicly accessible website, in whole or in part.  Sodium Shockers McDonald’s Big Mac = 940 mg Tim Horton’s Roast Beef and Cheddar Sandwich = 1260 Tim Horton’s Large Hot Chocolate = 310 mg Greco Works Pizza (2 large slices) = 2014 mg Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Chloride Chloride (Cl–) is an essential nutrient Involved in fluid and electrolyte balance Associated with sodium outside of the cell and potassium inside the cell Moves passively through membrane channels Part of HCl (remember digestion!) Abundant in foods, consumed as part of salt Deficiency and toxicity are both rare 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, 7 or posted to a publicly accessible website, in whole or in part. Potassium A cation, found inside cells Roles in the body: Fluid and electrolyte balance Nerve transmission and muscle contraction Sodium and potassium trade places Quickly reverts back to normal 1 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,8or rd posted to a publicly accessible website, in whole or in part. Potassium 1 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, 9 or posted to a publicly accessible website, in whole or in part. Potassium Linked with hypertension ↓ potassium + ↑ sodium = high blood pressure Deficiency is rare Toxicity Not due to food so no UL has been set Due to certain diseases or medications 2 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, 0 or posted to a publicly accessible website, in whole or in part. Phosphorus 2 1 or Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, posted to a publicly accessible website, in whole or in part. Fluid and Electrolyte Imbalance Causes of imbalance: Prolonged vomiting or diarrhea Heavy sweating Burns and traumatic wounds Some medications Solutes lost depend on why fluid is lost (e.g. lose sodium in sweat). Need to replace lost fluids and electrolytes. 2 2 or Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, rd posted to a publicly accessible website, in whole or in part. Fluid and Electrolyte Imbalance Dehydration Water lost > Water consumed = Negative water balance Many causes: Diarrhea Vomiting Fever or excessive sweating Unmanaged diabetes Diuretic use 2 3 or Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, rd posted to a publicly accessible website, in whole or in part. Fluid Balance Thirst 2 4 or Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, posted to a publicly accessible website, in whole or in part. Fluid Balance Heat Illnesses Heat cramps Heat exhaustion Subtle twitches to painful Profuse sweating trying to spasms cool body Excessive loss of water Could suffer heat collapse and sodium Cold become life-threatening Strenuous activity in hot heat stroke environments 2 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,5or posted to a publicly accessible website, in whole or in part. Fluid Balance Heat Illnesses Heat stroke Serious medical condition Sweating stops, body temperature increases Strenuous work + hot environments + low body water and electrolytes Water intoxication Causes hyponatremia 2 6 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Chapter Summary (1 of 2) This chapter: Explained how the body regulates fluid balance. Identified the main roles, symptoms of excess, and food sources for sodium. Identified the main roles, symptoms of excess, and food sources for potassium. 2 Understanding Nutrition, 3rd Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated,7or posted to a publicly accessible website, in whole or in part. Chapter Summary (2 of 2) Identified the main roles and sources for the electrolytes chloride and phosphorus. Described various heat illnesses and water intoxication. 2 8 Understanding Nutrition, 3 Canadian Edition. © 2023 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or rd posted to a publicly accessible website, in whole or in part.