A And P Ch 20 Fluids And Electrolytes Flashcards
Average body water vol
40 L
Water is 50-60% of adult body weight
Variations in body water volume are related to
Total body weight of individual
Fat content of body
More fat= less water
Adipose tissue= less water
Age related variations in body water volume
% of body water decreases rapidly in first ten years
Newborn- up to 80% total body weight
Older adults- water per pd of body weight decreases
Muscle tissue =high in water
As we age less muscle, more fat
Body fluid compartments
Extracellular
Intracellular
Extracellular fluid
Internal environment of body
Surrounds cells
Transports substances to and from cells
Types of extracellular fluid
Plasma- liquid part of whole blood
Interstitial fluid- surrounds cell
Transcellular fluid-lymph, joint fluids, cerebral fluids, eye humors
66% of fluids is in cells
Intracellular fluid
LARGEST FLUID COMPARTMENT
Solvent- facilitates Intracellular chemical reactions
Intracellular fluid is in every cell of the body
Relative volume of three body fluids
Plasma-3liters
Interstitial fluid-12 liters
Intracellular- 25 liters
Regulation of fluid output
Fluid output mainly urine volume adjust to fluid intake
Antidiuretic hormone (ADHfrom posterior pituitary gland) increases renal tubule reabsorption of NA and H2O
Which increases ECF (and total body fluid) by decreasing urine volume
Homeostasis of water volume
1st (primary)- adjust output to intake less urine
2nd (secondary)-adjust fluid intake. Drink more
If input and output are equal = no change in amt of water in body
four main sources of H2O volume
Water vapor when we exhale
Sweat that evaporates from skin
Urine output by kidneys
Water lost in feces
Three main sources of fluid intake
Liquids we drink
Water in the foods we eat
Water formed by catabolism AKA cellular respirations
Exchange of fluids by blood
Capillary blood pressure pushes water out of blood enter interstitial fluid
Blood protein concentration pools water enter blood from intititial fluid
Under usual conditions These regular plasma and interstitial fluid volume
Aldosterone
Restores normal ECF volume one levels decrease below normal
Hey too much aldosterone causes excess ECF volume and elevated total NA+ content in the in the body (edema)
Fluid imbalance
Dehydration and overhydration
Dehydration
Total volume of body fluids less than normal
Interstitial fluid volume shrinks first
If treatment is not given I see ICF and plasma volume decreased dehydration occurs when fluid output exceeds intake for an extended period
Overhydration
Total volume of body fluids greater than normal
Overhydration occurs when fluid intake exceeds output
Various factors may cause this such as
IV fluids given too fast or too much
Intentional water intoxication
Water intoxication may result from
Rapidly drinking large volumes of water
Hypertonic IV solutions
Water intoxication can happen in healthy individuals when water intake is so rapid or
Urinary mechanisms of water loss cannot keep up
Fluid Imbalances can occur
A normal temperatures hot weather and prolonged exercise
Importance of electrolytes in body fluids
NON-ELECTROLYTES are organic substances that do not break up and water such as glucose
ELECTROLYTES are compounds that break up of water they break into separate particles called ions such as Old Navy tablesaw sodium chloride
Electrolytes
Influence the movement of water between bodies fluid compartments
Are required for manycellular activities such as nerve conduction muscle contraction
Sodium (Na+)
Most abundant and important positively charged ion of plasma
Aldosterone increases Na+ reabsorption in kidney tubules
Major electrolytes
Sodium Na
Potassium K
Calcium Ca
Bicarbonate HCO
Chloride Cl
Protein
Electrolyte imbalances
Homeostasis of electrolytes-electrolyte balance related to intake and output for specific electrolytes
SODIUM IMBALANCE-(135-145hypernatrimia=headache, confusion
Hyponatremia-coma, death
CALCIUM IMBALANCE-(8.5-10.5)Hypercalcemia= muscle weakness, increased thirst
Hypocalcemia=muscle cram, muscle spasms
POTASSIUM IMBALANCE(3.5-5)-hyperkalemia=weakness,
Hypokalemia=cardiac arrest, cardiac dysrhythmias
