Renal Flashcards
Extracellular
Na
Cl
HCO3
Ca
Intracellular
K
Organic anions
Proteins
Mg
Protein (albumin) levels are highest in the _ and _ compartments
ICF
Vascular
Are membranes permeable to proteins
No
Oncotic (colloid osmotic) pressure
Pressure generated by large molecules (like proteins) in solution that are impermeable to membranes
How are ICF and ISF measured
Indirectly
ECF
Inulin, Na, thiosulfate
ICF
TBW-ECF=ICF
TBW
H2O
Plasma volume
I-albumin, Evans blue dye
Interstitial fluids
ECF-plasma=ISF
What drives ECF osmolality
Na and Cl
Na vasculature __ Na interstitial fluid ___ Na due to action of NaKATPase
> >
What causes increased ICF (Na)
Disrupted pump activity (hypoxia
Where Na goes water follows
ICF osmolality is driven by
K
ECF osmolality controls _ volume
ICF
Water enters of leaves ECF rapidly to balance osmolality of ECF and ICF
Osmotic equilibrium
Movement of water across cell membranes from higher to lower concentration as a result of osmotic pressure differences across that membrane
Osmotic presssure exerted across a membrane by a substance is also due to that membrane being impermeable to that substance
Mean forces tend to move fluid __
Outward
Total outward force
Plasma colloid osmotic pressure (28mmHg)
Total inward force
Outward (28.3)
Inward (28
What are the pressures
Mean capillary pressure (17.3)
Negative interstitial free fluid pressure (3)
Interstitial fluid colloid osmotic pressure (8)
How is ECF a reservoir
All water an solutes must pass through the ECF first
First calculate ECF then ICF
All solutes and water that enter or leave the body do so via ECF
ICF and ECF are in osmotic equilibrium
Equilibration occurs primarily by shifts of water, not solutes
Hypernatremia
> 146
Hyponatremia
<136
Hyper and hyponatremia is a __ problem
Water
What maintains the fluid distribution between plasma and ISF
Balance of hydrostatic and osmotic forces across capillaries
What determines ECF and ICF fluid distribution
Osmotic effect of small solutes across cell membranes
Isosmotic
Solutions that have the same osmolality as the ECF
When added to ECF, osmolality does not change , only the volume
Hyperosmotic
Osmolality greater than the ECF
When added to the ECF , osmolality increases and pulls water from the ICF into the ECF, resulting in an increase in ECF volume and a decrease in ICF volume
Hypoosmotic
Osmolality less than ECF
When added to ECF, osmolality decreases and water moved out of the ECF and into the ICF to equilibration. ECF and ICF volumes both increase
What give if want to dilute ECF and rehydrate cells
Hypotonic .45 salient
What administer if want to replace fluid loss and expand intravascular volume
Isotonic solution normal saline
What administer to treat severe hyponatremia
Hypertonic solution
3% saline
Prostagladins are protective of __
RBF
Prostagladins as buffers
Vasoconstriction effects of SNS/RAAS (the built in safety mechanism)
How do prostagladins with
Inhibits K channels in TAL, increasing Cl, impeding turnover of Na K 2 Cl channels, reducing NaCl reabsorption
NSAIDS and prostagladins
Interfere with PGE2 action, leading to Na retention
What kind of patient careful to give NSAIDS
Hypertensive patients, renal stenosis, patients on diuretics
Angiotensin II effect on RBF
Decrease
Decrease
ANP effect on RBF and GFR
Increase increase
Prostagladins effect on RBF and GFR
Increase increase
Sympathetic stimulation leads to what
Na K ATPase increase Na reabsorption at tubular epithelial cells
RAAS juxtaglomerular granular cells*mainly
Powerful vasoconstriction : afferent>efferent arteriole a1 adrenoceptors
INCREASED BP