fluid within cell membrane has highest concentration of potassium Nutrition Chapter 12 Water and the Major Minerals Water and the Body Fluids carries nutrients and waste products maintains structure of large molecules participates in metabolic reactions serves as solvent acts as a lubricant and cushion regulation of body temp maintains blood volume Water Balance water constitutes 60 of adults body weight most indispensible nutrient thirst lags behind the body s need for water o water intoxication hyponatremia sodium levels are so low in blood symptoms confusion convulsions death Signs of Dehydration p384 in book Water Balance and Recommended Intake Sources o Water o beverages not alcohol o foods fruits and vegetables o condensation reactions Losses o Urine lungs sweat and leces Recommendations o Needs vary fever out in the heat exercise o AI for total water includes the water you get from fruits and veg o 8 or 12 cups a day Health Effects o Meet bodily needs o Protects against urinary stones and constipation o Concentration alertness and short term memory Blood Volume and Blood Pressure Kidneys are central to blood volumes and pressure maintenance Antidiuretic hormone ADH o Produced by pituitary gland o Water conserving hormone Stimulates kidneys to reabsorb water Renin o Enzyme released by kidney cells when blood pressure is low Water retention with more water in blood more volume so bp o Kidneys reabsorb sodium Angiotensin is gonna go up o Renin hydrolyzes angiotensinogen to angiotensin I Convert to active form angiotensin 2 Aldosterone o Released from adrenal glands Release stimulated by angiotensin 2 o Signals kidneys Excrete potassium Retain sodium and thus water FLUID AND ELECTROLYTE BALANCE o Water follows electrolytes Electrolytes predominately outside of cell Na Cl o Electrolytes predom inside cell o K Mg Ph S Proteins regulate fluid movement o Attract water o Transport proteins Passage of ions across cell membranes Sodium potassium pump o Regulation of fluid and electrolyte balance Two sites Gi tract Kidneys Causes of imbalance o Prolonged vomiting or diarrhea o Heavy sweating o Burns o Traumatic wounds o Some medications Replacing lost fluids and electrolytes o Plain cool water and regular foods o Special replacement fluid THE MINERALS o Major vs trace minerals Variation amounts needed o Inorganic elements Always retain chemical identity Not destroyed by heat air acid or mixing Sodium Potassium Chloride oral replacement Therapy water sugar and salt o Helps maintain bod fluids one question on each of these Calcium Phosphorous Magnesium o Bone growth and health SODIUM o Roles in body Principal cation of extracellular fluid Primary regulator of volume Acid base balance Nerve impulse transmission Muscle contraction o Kidneys filter out and return what is needed o Reccomendations Average intake in U S exceeds the UL o Hypertension Salt intake attracts water into blood so higher volume and pressure DASH diet dietary approach to stop hypertension Low in sodium high in potassium fruits and veg high in calcium dairy lean meats whole grains o Bone Loss osteoporosis High slat intake is associated with increased calcium excretion Potassium as protective factor DASH diet recommendation o Food Sources Processed foods are not good More sodium o Deficiency hyponatremia o Toxicity Less potassium Actue edema and high bp Chronic hypertension CHLORIDE o Roles in body Major anion of extracellular fluids Fluid and electrolyte balance Part of hydrochloric acid HCL POTASSIUM o Deficiency and toxicity rare o Abundant In processed foods o Principal intracellular cation o Roles in body Help maintain fluid and electrolyte balance Maintain cell integrity Aids in nerve impulse transmission and muscle contraction o Recommendations and intakes Fresh foods richest sources Increase fruit and veg intake to meet AI o Hypertension o Deficiency o Toxicity Diets low in potassium increase BP Diets high in potassium lower BP and risk of stroke Increase BP muscle weakness salt sensitivity No UL Too many K salts or supplements but not from diet Kidneys accelerate excretion CALCIUM o Most abundant mineral in the body o Adequate intake Grows a healthy skeleton in early life Helps minimize bone loss in later life o Majority of bodys calcium is in bones and teeth 99 Part of bone structure Calcium bank o In bones o In teeth o In body fluids Calcium salts form crystals Hydroxyapatite Strength and rigidity to maturing bones Bone remodeling Fluoride stabilizes calcium crystals in teeth Helps maintain normal bp Extracellular calcium Participates in blood clotting Intracellular calcium Regulation of muscle contraction Transmission of nerve impulses Activation of some enzyme reactions Secretion of hormones Disease prevention HTN chol DM colon CA Obesity May help maintain healthy body weight o Inverse relationship with food sources Calcium balance Involves system of hormonses and vitamin d vit d enhances calcium eabsorption o Parathyroid hormone and calcitonin Organ system response o recommendations based on amount needed to retain calcium in bones o Intestines o Bones o Kidneys o Absorption 30 in adults efficiency and inadequate intakes peak bone mass o milk products adverse effects from supplements conceal milk products in foods most abundant other foods bioavailability fortified juice and foods o calcium and iron o deficiency peak bone mass by late 20s all adults lose bone with age begins 30 40 years old osteoporosis silent disease
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