Body Fluids. 07-Apr-11. Fluids. Fluids. Fluids. Fluids. There are different types of fluids in our bodies.

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1 Body Electrolyte Balance Substances composed of freely moving molecules Have the ability to conform to the shape of their container There are different types of fluids in our bodies % of a healthy adult s body is composed of fluids About 2/3 of this fluid is within body cells and is called intracellular fluid The remaining 1/3 is extracellular fluid 1

2 Extracellular fluids include Tissue fluid found between the cells within tissues and organs of the body Plasma, the fluid portion of blood that carries the blood cells The body fluid composition of tissue varies by Tissue type lean tissues have higher fluid content than fat tissues Gender males have more lean tissue and therefore more body fluid Age lean tissue is lost with age and body fluid is lost with it Electrolytes Body fluid is composed of Water Electrolytes: mineral salts dissolved in water, including: Sodium Potassium Chloride Phosphorus 2

3 Electrolytes Electrolytes carry electrical charges: Sodium (Na + ) and potassium (K + ) are positively charged Chloride (Cl - ) and phosphorus (as HPO 2-4, phosphate) h are negatively charged Electrolytes have an overall neutral charge due to the balances between electrolytes In intracellular fluid, K + and HPO 4 2- are the predominant electrolytes In extracellular fluid, Na + and Cl - predominate Functions of dissolve and transport substances Water is an excellent solvent because it can dissolve many different substances The dissolved materials, or solutes, include ions, sugars, amino acids, vitamins, and minerals Functions of account for blood volume. Blood volume is the amount of fluid in the blood Increased blood volume can cause blood pressure to rise Decreased blood volumes can cause low blood pressure 3

4 Functions of Functions of help maintain body temperature. The high heat capacity of water means that the temperature of our body fluids remains quite stable Sweating releases heat as the evaporation of water from the skin cools the skin and blood Functions of protect and lubricate body tissues. Cerebrospinal fluid protects the brain and spinal column Amniotic fluid protects the fetus Synovial fluid is a lubricant around joints Digestive secretions allow for easy passage of material Functions of Electrolytes Electrolytes help regulate fluid balance. Water follows the movement of electrolytes, moving by osmosis to areas where the concentration of electrolytes is high This allows for the controlled movement of fluids into and out of cells 4

5 Functions of Electrolytes: Osmosis Functions of Electrolytes Electrolytes help nerves respond to stimuli. Movement of Na + and K + across the membranes of nerve cells changes the electrical charge across the membrane This change in electrical charge carries the nerve impulse along the nerve cell Functions of Electrolytes Electrolytes signal our muscles to contract. The movement of calcium (Ca 2+ ) into a muscle cell stimulates the muscle to contract The Ca 2+ is pumped back out of the cell after the muscle contraction Maintaining Fluid Balance Any water lost from the body must be replaced Water is gained through beverages, food, and metabolic reactions Water is lost through urine, sweat, exhalation, and feces 5

6 Water Intake Water Balance Amount (ml) Water Removal Amount (ml) Liquids Kidney Foods Skin Metabolic Lungs 350 Maintaining Fluid Balance Loss of water Most water is lost through urine The kidneys control how much water is reabsorbed. Excess water is processed by the kidneys and excreted as urine Insensible water is lost tthrough hthe skin (sweat) or through the lungs during exhalation GI tract 150 Total Maintaining Water Balance Taking in water Most water enters the body through beverages Some foods have very high water contents Many fruits and vegetables are > 90% water Metabolic water is a product of many chemical reactions in the body and contributes 10-14% of the body s needs Functions of Water Essential For Life 6

7 Maintaining Fluid Balance Functions of water Essential for life Required for fluid and electrolyte balance and many metabolic reactions Recommendation for water Varies with climate, activity and body size Recommendation for adult men is 3.7 litres/day Recommendation for adult women is 2.7 litres/day Water What if you drink too much water? Becoming over hydrated is rare Can result in a dilution of sodium leading to hyponatremia, a life-threatening condition What if you don t drink enough water? Dehydration Infants and the elderly are especially vulnerable Water in Foods 100% Water, Club Soda 90 99% Fat Free Milk; strawberries, watermelon; lettuce, celery, spinach 80 89% Fruit juice; yogurt; apples; grapes; carrots; most fruits 70-79% Shrimp; bananas; corn; potatoes, avocado; cottage and ricotta cheese 50 59% Ground beef; hot dog; feta cheese Water in Foods 60 69% Pasta; legumes; salmon; ice cream; chicken breast 40-49% Pizza 30-39% Cheddar cheese, bagels; bread 20-29% Pepperoni sausage; cake; biscuits 10-19% Butter; margarine; raisins 1 9% Crackers; cereals; pretzels; taco shell; peanut butter, nuts 0 % Oils 7

8 Sodium Functions of sodium Fluid and electrolyte balance Associated with blood pressure and ph balance in the body Required for nerve impulse transmission Assists in the transport of certain nutrients (eg., glucose) into body cells Sodium Recommended intake Adequate Intake is 1.5 g/day (1500 mg/day) Upper level is 2.3 g/day (2300 mg/day) Sodium intakes Most sodium is consumed as sodium chloride and Canadians consume an average of 3092 mg sodium daily; 77 % is from processed foods At least 75% of Canadians consume above the UL Sodium Sodium content of foods Many high sodium foods can be replaced by a lower sodium alternative: Dill pickle (1731 mg) low sodium pickle (23 mg) Cured ham (1023 mg) pork roast (54 mg) Canned soup (695 mg) low sodium soup (480 mg) Potato chips (168 mg) baked potato (14 mg) Sodium What if you consume too much sodium? Hypernatremia is abnormally high blood sodium concentration Can happen to patients with congestive heart failure or kidney disease Results in high blood volume, edema, and high blood pressure 8

9 Sodium What if you don t consume enough sodium? Hyponatremia is an abnormally low blood sodium level Can result from prolonged vomiting, diarrhea, or sweating Has been seen in marathon athletes who consume too much water Potassium Functions of potassium Fluid and electrolyte balance Very important in muscle contractions and transmission of nerve impulses High potassium intake helps to maintain a lower blood pressure Potassium Recommended intake Adequate intake is 4.7 mg/day (4700 mg/day) Sources of potassium Processed foods are usually low in potassium Fresh fruit and vegetables and whole grains are good sources of potassium Potassium What if you consume too much potassium? Hyperkalemia is a high blood potassium level Can occur in patients with kidney disease Can alter normal heart rhythm resulting in a heart attack 9

10 Potassium What if you don t consume enough potassium? Hypokalemia is low blood potassium levels Can be seen in patients with kidney disease or diabetic acidosis Can occur when taking certain diuretic medications Chloride Functions of chloride Assists with maintaining fluid balance Assists the immune system Part of hydrochloric acid in the stomach Recommended intake Adequate intake is 2.3 g/day (2300 mg/day) Almost all chloride is consumed as NaCl Chloride What if you consume too much chloride? May lead to hypertension in salt-sensitive patients No DRI has been set for chloride What if you don t consume enough chloride? This is rare but can occur in people with eating disorders Medical Disorders Disorders related to fluid and electrolyte imbalance include: Dehydration Heat stroke Water intoxication Water intoxication Hypertension Muscle disorders 10

11 Dehydration Dehydration occurs when water loss exceeds water intake Commonly due to heavy exercise or high environmental temperatures. Infants and the elderly are more at risk Heat Stroke Heat stroke occurs if the body s temperature regulation mechanisms fail Occurs in hot, humid environments Symptoms include rapid pulse, hot, dry skin, high body temp, weakness Has been fatal for athletes during exercise in extreme heat Hypertension Hypertension is a chronic condition characterized by high blood pressure Systolic pressure over 140 mm Hg Diastolic pressure over 90 mm Hg May not show symptoms Increases a person s risk of heart disease, stroke, kidney disease Muscle Disorders Electrolyte imbalances can result in seizures or muscle cramps Electrolyte imbalances cause changes in nervous system function N t h lt Nervous system changes can alter proper muscle function 11

12 Hypertension Does high sodium intake cause hypertension? Most health organizations recommend a reduced sodium intake Other ways to reduce blood pressure include: Maintain healthy body weight Increase physical activity Reduce stress Functions of Electrolytes Fluid and electrolyte balance Phosphorus Functions of phosphorus The major intracellular negatively charged electrolyte is HPO 2-4 Required for fluid balance Critical role in bone formation Regulates biochemical pathways by activating or deactivating enzymes Found in ATP, DNA, RNA 12

13 Phosphorus Recommended intake RDA for phosphorus is 700 mg/day Sources of phosphorus Widespread in many foods Found in high amounts in foods that contain protein (e.g., meat, milk, eggs) Phosphorus What if you consume too much phosphorus? High blood phosphorus can occur with kidney disease, after taking too many vitamin D supplements, or over consuming phosphorus-containing antacids Causes muscle spasms, convulsions Phosphorus What if you don t consume enough phosphorus? Deficiencies of phosphorus are rare Those at risk are premature infants, elderly people consuming poor diets, or people who abuse alcohol 13