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Chapter Lecture Chapter 9: Nutrients Involved in Fluid and Electrolyte Balance © 2017 Pearson Education, Inc Body Fluids • Body fluid is the liquid portion of cells and tissues • Characterized by its ability to move freely and changeably, adapting to the shape of the container that holds it About 5070% of healthy adult body weight â 2017 Pearson Education, Inc Body Fluids • Intracelluar fluid: within the cell • 2/3 of body fluid • Extracellular fluid: outside the cell • 1/3 of body fluid • Interstitial fluid flows between cells that make up a particular tissue or organ (muscle, liver) • Intravascular fluid is the water in the blood and lymph • Plasma transports blood cells within arteries, veins, and capillaries © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Body Fluids • 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 than females • Age: decrease in body water results partly from loss of lean tissue as people age © 2017 Pearson Education, Inc Electrolytes • Electrolytes are dissolved substances that disassociate in solution into electrically charged particles called ions • Positive charge (cations): sodium, potassium • Negative charge (anions): chloride, phosphorus • Predominant electrolytes • Extracellular fluid: sodium, chloride Intracellular fluid: potassium, phosphorus â 2017 Pearson Education, Inc Functions of Body Fluids • Fluids dissolve and transport substances • Water is an excellent solvent because it dissolves a variety of substances • Water-soluble substances are readily transported in the bloodstream: amino acids, glucose, water-soluble vitamins, minerals, some medications • Fatty substances must be attached to or surrounded by water-soluble proteins © 2017 Pearson Education, Inc Functions of Body Fluids • Fluids account for blood volume • Appropriate body fluid levels are essential for maintaining healthful blood volume • Blood pressure increases when blood volume rises • High blood pressure (hypertension) is a risk factor for heart disease and stroke • Low blood pressure can cause people to feel tired, confused, or dizzy • Kidneys help to regulate blood volume and blood pressure © 2017 Pearson Education, Inc Functions of Body Fluids • Fluids account for blood volume • Antidiuretic hormone (ADH) released from the pituitary gland stimulates the kidneys to reabsorb water, reducing urine output • Enzyme renin secreted from the kidneys responds to decreased blood pressure; catalyzes the conversion of blood protein angiotensinogen to angiotensinogen I © 2017 Pearson Education, Inc Functions of Body Fluids • Fluids account for blood volume • Angiotensin I is converted to Angiotensin II (vasoconstrictor); increases blood pressure • Hormone aldosterone secreted from the adrenal glands signals the kidneys to retain sodium and chloride, thereby retaining water, increasing blood pressure, and decreasing urine output © 2017 Pearson Education, Inc Phosphorus (cont.) • What happens if you consume too much phosphorus? • High blood phosphorus can occur among people with kidney disease or when taking too many vitamin D supplements • Causes muscle spasms, convulsions • What if you don't consume enough phosphorus? • Deficiencies of phosphorus are rare © 2017 Pearson Education, Inc Disorders Related To Fluid And Electrolyte Imbalance • • • • • • • • Dehydration Heat stroke Water intoxication Hypertension Neuromuscular disorders Kidney disorders Congestive heart failure Obesity © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Dehydration • Dehydration occurs when fluid loss exceeds fluid intake • Commonly due to heavy exercise or high environmental temperatures • Elderly and infants are at increased risk © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Heat Stroke • Heat stroke occurs from failure in the body's heat-regulating mechanisms • Hot, humid environments • Symptoms: rapid pulse, hot and dry skin, high body temperature, loss of consciousness • Fatal during exercise in extreme heat • Stop exercising when feeling dizzy, lightheaded, disoriented, or nauseated © 2017 Pearson Education, Inc Water Intoxication • Overhydration (water intoxication) can occur, but it is rare • Kidneys retain too much water, causing overhydration and hyponatremia • Documented cases of deaths among college students (hazing rituals) © 2017 Pearson Education, Inc Hypertension • Hypertension: major chronic disease characterized by high blood pressure • Often without symptoms • Increases a person's risk of heart disease, stroke, kidney disease • Can reduce brain function, impair physical mobility, and cause death • Systolic pressure over 140 mm Hg • Diastolic pressure over 90 mm Hg © 2017 Pearson Education, Inc Hypertension (cont.) • What causes hypertension? • Primary (or essential) hypertension: unknown cause for 90–95% of cases • 5–10% of cases are caused by kidney disease, sleep apnea, and chronic alcohol abuse • Salt sensitivity: about 2/3 adults with hypertension © 2017 Pearson Education, Inc Hypertension (cont.) • Recommendations for reducing hypertension: • Losing weight • Regular exercise • Limiting alcohol intake • Reducing sodium intake • Eating more whole grains, fruits, vegetables, and low-fat dairy foods • DASH diet • Avoid tobacco products © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Hypertension (cont.) • Medications • Help in normalizing blood pressure • Should also continue to practice healthful lifestyle changes • Hypertension: "the silent killer" • Often no obvious symptoms of this disease • Importance of regular blood pressure check © 2017 Pearson Education, Inc Neuromuscular Disorders • Electrolyte imbalances can alter nervous system and muscle function • Seizures: uncontrollable muscle spasms • Muscle cramps: involuntary, spasmodic, and painful muscle contractions © 2017 Pearson Education, Inc Kidney and Heart-Related Disorders • Kidney disorders • Kidneys have major role in regulation of fluid, electrolyte, and acid-base balance • Kidney disease can lead to edema and fluid retention • Congestive heart failure • Heart can no longer pump adequate supply of blood throughout the body • Heart can fail on the left or right sides, with varying consequences â 2017 Pearson Education, Inc Obesity Popularity of sweetened beverages (U.S.) • 20% of calories from beverages: sweetened soft drinks, fruit juices, sweetened bottled waters, energy drinkds, bottled teas, specialty coffee • Appetite not curbed: extra calories from drinks are not compensated for by eating less • Displace more nutritious beverages such as milk (source of protein, calcium, vitamin D, and other nutrients important for bone health) © 2017 Pearson Education, Inc ... Body fluid is the liquid portion of cells and tissues • Characterized by its ability to move freely and changeably, adapting to the shape of the container that holds it • About 50–70% of healthy... • Sweating releases heat as the evaporation of water from the skin cools the skin and blood © 2017 Pearson Education, Inc © 2017 Pearson Education, Inc Functions of Body Fluids • Protect and... concentration of solute is high • This action provides a means to control movement of water into and out of the cells • Osmotic pressure keeps electrolytes in solution from drawing liquid toward them
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