Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
what is homeostasis? |
-Stateof equilibrium in body - Naturallymaintained by adaptive responses Inorder to achieve homeostasis -Bodyfluids and electrolytes are maintained within narrow limits |
|
What is the water % of Adults, Older adults, and infants? |
-60%of body weight in adult -45%to 55% in older adults -70%to 80% in infants |
|
When does water content vary? |
gender,body mass, and age |
|
The nurse knows that older adults are more prone to fluid volume alterations for which of the following reasons? a.They have decreased thirst sensation. b.Their kidneys have an increase in glomerular filtration. c.They are at risk for increased excretion of medications. d.They have decreased stomach-emptying time. |
a) they have decreased thirst sensation |
|
What are the 2 major body fluid compartments? |
-Intracellularfluid (ICF)Locatedwithin cellswhish makes up Two-thirdsof body water and 42%of body weight -Extracellularfluid (ECF)One-thirdof body water; 17% of total body weight Betweencells (interstitial fluid), lymph, plasma, and transcellular fluid |
|
Where do you find transcellular fluid? |
-Cerebrospinalfluid -Gastrointestinaltract -Pleuralspaces -Synovialspaces -Peritonealfluid spaces |
|
What is thrid-spacing? |
Occurs when too much fluid moves from the intravascular space (blood vessels) into the interstitial or "third" space-the nonfunctional area between cells. This can cause potentially serious problems such as edema, reduced cardiac output, and hypotension. |
|
How much transcellular fluid is in the body? |
Approx 1L |
|
What are the functions of body fluid? |
-Transportnutrients, electrolytes, and oxygen -Carrywaste products away -Necessaryfor regulation of body temperature -Lubricatesjoints and membranes and aids in digestion |
|
What are electrolytes |
Substanceswhose molecules dissociate (split) into ions (charged particles) when placedinto water |
|
What does dissociate mean? |
split into ions |
|
What is an ion? |
A charged particle |
|
What are cations? |
Positively charged ions- Na+, K+, Ca+, Mg+ |
|
What is an anion? |
Negatively charged ions- HCO3-,Cl-, PO4- |
|
How do you measure electrolytes? |
Internationalstandard is millimolesper litre(mmol/L) |
|
In ICF what is the prevalent anion and cation? |
Anion is PO43- (phosphate) Cation is K+ (potassium) |
|
In ECF what is the prevalent anion and cation? |
Anion is Cl- (chloride) Cation is cation is Na+(sodium) |
|
What is the Mechanisms Controlling Fluid and Electrolyte Movement |
-Diffusion -Facilitateddiffusion -Activetransport -Osmosis -Hydrostaticpressure -Oncoticpressure |
|
What is Diffusion? |
Movement of molecules from high to low concentration -Occurs in liquids, solids, and gases -Membrane separating two areas must be permeable to diffusing substance -Requires no energy |
|
What is facilitated diffusion? |
-Movementof molecules from high to low concentration without energy - Usesspecific carrier molecules to accelerate diffusion |
|
What is active transport? |
Processin which molecules move against concentration gradientExternalenergy required -ATPproduced in the mitochondria -Example:sodium–potassium pump |
|
What is Osmosis? |
-Movementof waterbetween two compartments by a membrane permeable to water but not to solute - Movesfrom low solute to high solute concentrationRequiresno energy |
|
What is Osmotic pressure? |
Amount of pressure required to stop osmotic flow of water Determined by concentration of solutes in solution. Measured as Osmolality This is what is typically tested to evaluate concentration of plasma and urine Normal is 280-300. Changes in extracellular osmolality can cause changes in both ICF and ECF volume |
|
What is hydrostatic pressure? |
Force within a fluid compartment In the blood vessels hydrostatic pressure -is the force generated by the contraction of the heart -Decreases as the blood moves through the arteries Major force that pushes water out of vascular system at capillary level |
|
What is Oncotic pressure? |
Osmoticpressure exerted by colloids in solution (colloidal osmotic pressure)Proteinis major colloid in blood◦Largemolecules that cannot easily cross out of vascular space◦Attractwater ◦Pullfluid from intracellular compartment into the vascular space |
|
What is Carrier-mediated transport? |
moves molecules across the plasma membrane, It can be active of passive. Examples are active transport and facilitated diffusion |
|
what is Insensible water loss? |
continuous, gradual movement of water from the respiratory and skin epithelium, amounting 20-25mL/hour. Approx 600mL/day |
|
How much in mL do lungs a day? |
400mL/day |
|
What is sensible water loss? |
visible water loss from the skin regulated by the sympathetic nervous system, which activates sweat glands. |
|
What are Osmoreceptors? |
the continually monitor the serums osmotic pressure. Controls thirst. |