body fluid
-primarily water
-contains gases (CO2 & O2)
-contains solutes
electrolytes
solutes that develop an electrical charge when dissolved in water
(sodium, potassium)
nonelectrolytes
solutes that do not conduct electricity
(glucose, urea)
60%
what percent of body weight in a typical adult is body fluid
(decreases with age)
adipose tissue
age
sex
total body water content varies with what 3 factors?
Intracellular fluid (ICF)
fluid within cells
-40% of body weight (2/3 of body fluid)
-essential for cell function and metabolism
Extracellular fluid (ECF)
fluid outside the cells
-20% of body weight (1/3 of body fluid)
-carries water, electrolytes, nutrients, and oxygen to cells and removes waste products of cellular metabolism
intersitial fluid
extracellular fluid in the spaces between cells
-excess fluid here = edema
intravascular fluid
extracellular fluid within the blood (plasma)
-main function is to transport blood cells
transcellular fluid
extracellular fluid, includes specialized fluids that are contained in body space
-cerebrospinal, pleural, peritoneal, synovial fluid, and digestive juices
cations
electrolytes that carry a positive charge
-sodium, potassium, calcium, magnesium, hydrogen ions
anions
electrolytes that carry a negative charge
-chloride, phosphate, bicarbonate
passive transport
the movement of substances across a cell membrane without the use of energy
-osmosis, diffusion, filtration
osmosis
movement of WATER across a membrane from an area of LOW to HIGH concentration
osmolality
concentration of solutes creating pressure in the body fluid
sodium
greatest determinant of serum osmolality
isotonic solution
same solute concentration on both sides of membrane (so no mvmt of water will occur)
-useful for client with hypotension or hypovolemia (FVD)
hypotonic solution
Solute concentration is less than that inside the cell; cell gains water (swells)
-used for hyperglycemia (diabetes ketoacidosis)
hypertonic solution
Solute concentration is greater than that inside the cell; cell loses water (swells)
-used to increase blood volume (with burns or hemorrhage)
-stabilizes BP, increases urine output, reduces edema
diffusion
movement of SOLUTES through a cell membrane from an area of HIGH to LOW concentration
-untill dynamic equilibrium
filtration
movement of WATER AND SMALL PARTICLES from an area of HIGH PRESSURE to one of LOW PRESSURE
-pressure created when hydrostatic pressure exceeds orthostatic pressure -- force moves water and solutes
hydrostatic pressure
force created by fluid that pushes fluid out of the vessel, responsible for normal circulation of blood
osmotic pressure
power of a solution to draw in water
active transport
Energy-requiring process that moves material across a cell membrane against a concentration gradient (LOW to HIGH concentration)
-ATP
-sodium-potassium pump
fluid intake
-80% from drinking fluids (2700-3500 mL/day)
-20% from food and metabolism
-thirst is major regulator (thirst center in hypothalamus)
hypothalamus
changes in plasma concentration (osmolality) signal the thirst center in the ___ --> urge to drink
urine
skin
lungs
feces
common sources of fluid loss (4)
kidneys
principle regulator of fluid and electrolyte balance
ADH (antidiuretic hormone)
causes kidneys to retain fluid
-if fluid volume is low, this is released
Renin-Angiotensin System
when ECF volume is decreased, retain sodium and water
-directs adrenal cortex to release aldosterone
thyroid hormone
affects fluid volume by influencing cardiac output
Aldosterone
salt-retaining hormone" which promotes the retention of sodium by the kidneys, and excretion of potassium
-released via renin-angiotensin system
3.5-5.0
Potassium (K+) normal range
135-145
Sodium (Na+) normal range
8.5-10.5
Calcium (CA2+) normal range
1.6-2.6
Magnesium (Mg2+) normal range
95-105
Chloride (Cl-) normal range
22-26
Bicarbonate (HCO3-) normal range
35-45
Carbon dioxide (PCO2) normal range
7.35-7.45
pH normal range
Sodium (Na+)
regulates fluid volume
-reabsorbed and secreted thru kidneys
-deficiency may be caused by excess water
-major cation in the ECF
potassium (K+)
-regulates cardiac rhythm
-excreted thru kidneys, regulated by aldosterone
-loss triggered by diuretics--> dysrhythmias
-major cation in the ICF
calcium (Ca2+)
#NAME?
Magnesium (Mg2+)
#NAME?
acidosis
pH < 7.35
alkalosis
pH > 7.45
acid
any compound that contains hydrogen ions (H+)
base
compound that accepts (combines with) hydrogen ions