Chapter 14 Water and Major Minerals Introduction Water No kcals Not 2nd most important component to life 1st oxygen Digestion absorption metabolism Functions 1 Regulation of Water absorbs heat and moves away from body core Evaporates or sweat 2 Solvent for Hydrolysis 3 Saliva aids ability to swallow food Mucus in GI Joints Eyeballs Distribution Distribution of body water Infants of body weight Young adults of body weight Older adults 50 of body weight Compartmentalization Adipose Muscle 75 Bones 20 Teeth 10 Women have more adipose less body water then men Water Compartments figure Maintenance of fluid and electrolytes Pressure necessary to stop flow of water through membrane Glucose amino acids electrolytes urea in cell need water to stay in solution membrane Cell membranes are semi permeable Keeps some things in cell and other out of the cell Maintenance of fluid and electrolytes Pressure inside vessels the is produced by heart Oncotic pressure Large protein in fluid stay in capillary bed Temporary dehydration leads to build up of water in capillary All 4 maintain H2O in tissues Fluid Balance Water shifts freely in and out of cells Controlled by concentration Osmatic pressure semi permeable membrane hydrostatic pressure oncotic pressure Regulation of water balance 1 produces more concentrated blood hemoconcentration Hypothalamus detects this change 2 is activated Leads to an increase in ADH 3 Increase in Antidiuretic Hormone ADH Leads to an increase in reabsorption of water at kidneys Regulating the amount of water eliminated Vary with body size physical activity environmental conditions and dietary Water Needs intake AI daily adult male daily adult female Based on 80 fluid intake 20 food intake Water Deficiency dehydration loss of water can risk death The causes of dehydration include Not drinking enough water Vomiting Diarrhea Excessive sweating such as from fever or exercise Excessive urine output diabetes or diuretic drugs Water Toxicity Excessive intake of water hemodilution Poor coordination and confusion Death due to low electrolytes Seen in marathon runners Sports drinks help to balance osmotic activity in blood Introduction to Minerals Minerals are divided into 2 categories Greater than 100 mg day trace elements Less than 100 mg day Sodium Distribution Extracellular cation Na Throughout entire body Absorption metabolism Absorb most from diet Excess Important in water balance Tries to equalize with cell Na K pump Table salt 40 sodium 60 chloride Sodium Functions Muscle contraction Acid base balance Conduction of nerve impulses Regulation Hormone that stimulates reabsorption of sodium by kidney Sodium Deficiency Deficiency is rare May be due to excessive Losing 2 3 of body weight Signs of deficiency Muscle cramp nausea vomiting dizziness shock coma Normally kidney will respond by conserving sodium Adequate Intake is 1500 mg for adults Daily Value is mg day Typical intake is 2300 4700 mg day individuals should restrict intake Sodium Needs Sodium Disturbances in sodium metabolism high blood pressure Salt sensitive hypertension Increased salt intake high BP High sodium intake doesn t cause HTN just aggravates Potassium Distribution Intercellular cation K All cells in body Absorption metabolism Absorbed through GI tract Excess excreted Potassium Functions Increase cell count need K to fill cells Fluid balance Na K pump transmission Associated with lowering blood pressure Low blood potassium Potassium Regulation Muscle cramps confusion constipation irregular heart beat heart failure When causes Na to be reabsorbed K is excreted Increased sweating leads to increased K loss from blood Overtime low K intercellular Cramping will occur Serum K is maintained at expense of cellular K Potassium Sources Banana Sports drinks Milk Legumes Meats Requirements RDA Typical diet 2000 6000mg d Diuretics block reabsorption of electrolytes Need additional K Chloride Distribution Extracellular anion Cl Absorption metabolism From NaCl Functions HCl Acid base balance in blood Nerve function High intake may cause high blood pressure When Na is reabsorbed so is Cl Requirements RDA 750 mg d Sources Soy sauce Processed foods Chloride Regulation Hypertension HTN Why Control Blood Pressure Systolic BP Diastolic BP example mmHg To prevent Cardiovascular disease Poor circulation Kidney disease Stroke decline in brain functions African Americans most at risk Causes of HTN Aging Atherosclerosis Obesity increased fat mass and circulation Elevated insulin insulin resistant adipose cells Excess alcohol usually reversible Minerals and HTN Blood pressure increases with intake Fluid retention leads to increased blood volume Other minerals 1000 mg per day lowers blood pressure 2 4 gm of potassium per day lowers blood pressure Magnesium may lower blood pressure Diet rich in fruits vegetables vitamin C Calcium Distribution Needed in amount in the body 2 of body weight is calcium 1 of calcium is outside bone Aids in muscle concentration Calcium Absorption and Metabolism Into small intestine via active transport Makes calcium binding protein in SI Under average conditions less than 1 3 or 30 of calcium ingested is absorbed 60 of calcium absorbed if chronic low intake Calcium Absorption and Metabolism Factors that enhance calcium absorption Lactose Vitamin D Growth hormone Factors that calcium absorption Oxalic Acid beets spinach Phytic Acid grains seeds nuts High phosphorus intake Calcium Functions Bone formation maintenance Tooth development Regulation of muscle contraction and relaxation Other Activate enzymes Calcium regulation Regulatory mechanisms ensure maintenance of intracellular and extracellular concentrations of calcium is maintained via secretes calcitonin Calcitonin Stimulates osteoblasts to build new bone using blood calcium Decreases the rate of vitamin D activation Parathyroid hormone PTH raises blood calcium Calcitonin lowers blood calcium Calcium regulation If blood calcium is too high Calcium Requirements AI 19 50 years 1000 mg day 51 years 1200 mg day 3 4 glasses of milk day UL mg d Sources Milk Yogurt Cheese Tofu Cooked navy beans Cooked broccoli Calcium deficiency With intake Plasma calcium is maintained to the detriment of the bones Low calcium hypocalcemia can result in muscles spasm This could lead to death by asphyxiation if respiratory muscles go into Calcium deficiency spasm Long term low calcium intake and loss of bone density Possibly causes include Calcium deficit Decreased efficiency