WEEK 12 Flashcards
(49 cards)
2 major compartments of body fluids
Intracellular
Extracellular
Transcellular fluid
Fluid separated from other fluids by a cellular barrier
Very small % of body fluids
Eg: CSF, pericardial, pancreatic, pleural, intraocular
fluid, biliary, peritoneal and synovial fluid
interstitial fluid
bathes, surrounds cells
intravascular fluid
blood plasms in vascular system
Brain-Kidney Interaction
serum osmolality increases ,
the brain stimulates release of antidiuretic hormone (ADH)
“vasopressin” to act on the kidneys to increase
REABSORPTION of water which decreases the excretion of
urine and increases the blood volume in the body.
4 processes for body fluid movement
osmosis, diffusion, filtration, active transport
osmolality
describes concentration of a solute to water
osmotic pressure
drawing power of water and depends on the # of molecules in a solution
A solution with high solute concentration has high _____ and draws water _______
osmotic pressure, towards itself
What is an isotonic solution and what are some examples?
a solution with the same osmolarity as blood plasma. expands body’s fluid volume w/o causing a fluid shift from one compartment to another. examples are normal saline (aka 0.9 sodium chloride)
What is a hypertonic solution? how does it work and what are some examples?
it is higher in cocentration and thus has higher osmotic pressure than the surrounding body cells. pulls fluid from cells causing crenation and increasing fluid in the vascular compartment. eg, 3% sodium chloride.
What is a hypotonic solution? how does it work, and what are some examples?
it is less concentrated than the fluid in the surrounding cells. has lower osmotic pressure, so it pushes fluid into the surronding cells and out of the vascular compartment. EG half normal saline
Process where SOLVENTS & SOLUTES (coffee &
sugar) move across the membrane together
Filtration
Hydrostatic pressure
pushes fluid out of a system
Eg. Sodium-Potassium-ATPase pump
ATPase moves 3 sodium ions out of the cell for every 2
potassium ions that it pumps in
Diffusion in the Body (example)
Eg. When carbon dioxide diffuses from the
bloodstream across the membrane of the alveoli so
that it can be exhaled
Filtration in the Body (example)
arterial end
hydrostatic
pressure exceeds colloid osmotic pressure, so fluid &
diffusible solutes (nutrients) move out of the
capillary into the interstitial space
venous end
colloid osmotic
pressure exceeds hydrostatic pressure, so fluid &
some solutes (waste products) move into the
capillary from the interstitial space
Hypovolemia
SOTONIC DEHYDRATION, FLUID
VOLUME DEFICIT a lack of water AND electrolytes
and therefore a decrease in blood volume.
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Actual Dehydration
lack of fluid in the body
Relative Dehydration
involves a shift of water to
the interstitial space.
What would happen if you gave someone excessive D5W?
overhydration
antidiuretic hormone
causes body to retain water.
where is ADH stored?
posterior pituitary gland
ADH makes renal tubules and collecting ducts more permeable to water, which ____________
causes water to return to the systemic circulation, diluting the blood and decreasing osmolarity.
