Fluid Electrolyte Balance HLTH 120 N Lecture 9

Fluid & Electrolyte Balance HLTH 120 N; Lecture 9

Objectives �List 3 ways fluid composition varies. �Identify the 4 electrolytes and their 3 functions. Identify the other mineral essential for muscle contraction. �Indicate the 4 main functions of body fluids. �Know your recommendations for water, sodium & potassium. �Explain how to effectively hydrate to support exercise �Describe what occurs with dehydration, heat stroke, and hypertension.

Body Fluid �The liquid portion of cells and tissues �Able to move freely, adapting to the shape of the area that contains it �About weight % of healthy adult body

Fluid composition varies by: �Tissue ◦ type than tissues have higher fluid content tissues �Gender ◦ usually have more lean tissue, so they have more. �Age ◦ With age, lean tissue is lost so body water.

� Intracelluar fluid: within the cell ◦ � of body fluid Extracellular fluid: outside the cell ◦ of body fluid ◦ Interstitial fluid flows between cells that make up a particular tissue ◦ Intravascular fluid is in the blood and lymph

Body Fluid Functions �Dissolve and transport substances ◦ Water is an excellent solvent ◦ Water-soluble substances are easily transported in the bloodstream: � ◦ Fatty substances?

Fluid Functions cont. �Account for blood volume ◦ Correct body fluid levels maintain a healthful blood volume ◦ Blood pressure when volume rises ◦ Low blood volume = blood pressure � ◦ Kidneys help regulate blood volume and pressure

Blood Volume/Pressure Regulation �Renin responds to decreased pressure �Anti-diuretic hormone ◦ �Angiotensin II (vasoconstrictor) �Aldosterone ◦ signals kidneys to retain sodium &

Fluid Functions Cont. �Help maintain body temperature ◦ Must be within a safe range ◦ Only sustained high heat can increase body temperature ◦ releases heat as water evaporates to cool skin and blood

Fluid Functions Cont. �Protect and lubricate tissues Examples: ◦ Cerebrospinal fluid ◦ Amniotic fluid ◦ Synovial fluid lubricates ◦ Tears cleanse & lubricate ◦ Saliva moistens food for swallowing

Fluid Function Recap � �

Electrolytes �Predominant electrolytes ◦ Extracellular fluid: ◦ Intracellular fluid: , chloride , phosphorus �Dissolved substances that disassociate in solution into electrically charged particles ◦ Positive charge: ◦ Negative charge: , .

Electrolyte Functions �Help regulate fluid balance ◦ Cell membranes are permeable to water, not electrolytes ◦ Electrolytes move with the help of carrier proteins, and water follows to areas of concentration Normal Too many intracellular solutes; cell will burst Too many extracellular solutes; cell will shrivel

Electrolyte Function Cont. �Enable nerves to respond to stimuli ◦ Nerve impulses are initiated at nerve cell membranes in response to a change in electrical charge ◦ Sodium & potassium ensure nerve impulses are generated, transmitted, and completed

Electrolyte Functions Cont. �Signal muscle contractions ◦ Muscles contract in response to stimulation of nerve cells ◦ Influx of into the muscle causes contraction ◦ Muscles relax after contraction once the electrical signal is complete and calcium is pumped out of the muscle cell

Water �Supports �Fluid all body functions Recommendations: ◦ Women: Men: �Can be very individualized �Lost water must be replaced � Best Food Sources:

Thirst & Fluid Balance �Like hunger, thirst is signaled by the with… ◦ Increased salt & substances in blood ◦ Reduced blood volume & pressure �Causes? ◦ Dry mouth and throat from reduced saliva �Anti-diuretic hormone will signal the to retain water

Water Loss �Sensible water loss ◦ ◦ �Insensible water loss ◦ Skin (not sweating) or lungs �Significant loss ◦ Illness, injury, high altitude, pregnancy, breastfeeding, diuretics

Water Balance Issues �Deficiency ◦ One of the leading causes of death around the world is dehydration. ◦ Hypernatremia: �Toxicity ◦ Hyponatremia: dilution of blood sodium �Very rare; occurs mostly in.

Sodium charge �Functions � -cellular ◦ Exchanges with potassium for fluid balance, p. H balance, blood pressure ◦ Transmits nerve signals ◦ Aids in glucose absorption �RDA: ◦ Most Americans consume: ◦ AHA, ADA recommend under:

Hypernatremia/High intake Hyponatremia/Low intake ◦ ◦ ◦ blood pressure ◦ Poor ◦ ◦ Sodium Imbalance function

Potassium �Functions: ◦ Fluid balance, nerve impulses �RDA: �Sources �Toxicitiy – ◦ weakness, vomiting, irregular heartbeat �Deficiency- ◦ weakness, paralysis, confusion, high BP

Chloride �Functions: ◦ Fluid balance, nerve impulses ◦ In the stomach as , aids white blood cells � Best Source: �Deficiency is rare

Phosphorus �Role: ◦ ◦ Component of body’s energy source: 80% of body phosphorus is in: Buffering agent In the cell membrane, forms: �Sources: meat, nuts, seeds, fish, veggies ◦ High amounts in �Toxicity: ◦ Causes spasms & convulsions ◦ Common in renal disease patients

Dehydration �Fluid losses ◦ Causes: �Classified �Small fluid intake by % weight loss from fluids losses: �Severe loss: ◦ Sleeplessness, nausea, flushed skin, poor concentration �Untreated: cardiac arrest, coma, death

Fluid replacement & exercise �Consume water before, during, after ◦ 2 -3 hours prior: ◦ 30 -60 min prior: ◦ During <1 hr: ◦ During >1 hr: �Measure body weight before & after ◦ For each lb lost, consume .

Urine Color Chart

Heat Stroke �Fatal heat illness ◦ Failure of body’s heating mechanisms � Most vulnerable? ◦ More muscle mass = greater heat production �Ability to lose heat through sweat very limited in humid environments

Hypertension �Inability to maintain blood pressure in a healthy range � % of US adults hypertensive �Increases �Reduces mobility risk for: brain function, impairs

Type of blood pressure �Systolic ◦ Pressure arteries exert during contraction. __________ �Diastolic ◦ Pressure in arteries during �Optimal: �Pre-hypertensive: �Hypertensive: .

Causes of hypertension � 5 -10% from kidney disease, sleep apnea, alcohol abuse �Over half have salt sensitivity ◦ Blood pressure will increase or decrease based on sodium intake �Others are salt resistant ◦ We now know not everyone will improve their blood pressure by reducing salt intake

5 lifestyle changes � ◦ 5 -10% � �

The DASH diet � �Low-fat & high fiber �Encourages potassium, calcium, magenesium ◦ servings fruits & vegetables/day �Sodium < 3 g �Blood pressure lowers within _____ �The lower sodium intake, the better

Fluid & electrolyte considerations �Neuromuscular issues: ◦ Seizures – due to nerve impulse issues ◦ Muscular dystrophy ◦ Muscle cramps – involuntary spasms �Obesity ◦ 21% of calories come from beverages ◦ Researchers believe sweetened beverages contribute to half the rise in calorie intake

DASH diet assignment �Create a 2, 000 calorie diet meeting DASH diet guidelines… just create it, you don’t have to eat it �Enter the diet into My. Diet Analysis ◦ (Do not include this day in your Diet Analysis project data) �Turn in the list of foods with the report of nutrients for that day � 1 paragraph: How does this diet compare to your own? Should it only be recommended with