Body Fluid Compartments Flashcards
Water always moves from ____ osmolality to ____osmolality
low, high
What is normal Sodium plasma
140
What is normal ICF potassium
150
What is normal Clhoride plasma
102
What is normal bicarbonate plasma
24
What is normal protein ICF
130
How is the difference between ICF and ECF generated is they have the same osmolality?
Cells have a negative charge because of 1. sodium-potassium ATPase (cell is more permeable to K than Na and resting membrane potential is close to K equilibrium potential) 2. “Fixed” intracellular polyanions - organic phosphates and proteins, 3. Multiple ion channels
What happens on a salt only diet?
the cells shrink as water moves out to less the osmolarity
What happens if we drink water alone?
lowers ECF sodium concentratiuon and osmolality, both ECF and ICF volume increases, until you pee it out, inhibiion of vasopression also happens
What is hypoatremia
it is when salt is ECF is low and water in ICF is high
What is hypernatremia
it is when salt is ECF is high and the water in ICF is low
what is oncotic pressure?
it is an osmotic force due to charged proteins mainly albumins
How do you measure fluid movement across capillaries?
Fluid flux = permeability x (hydrostatic pressure gradient - oncotic pressure gradient)
Why does edema happen
It is increased ISF volume:
Increased capillary hydrostatic pressure (heart failure)
Decreased plasma albumin concentration (liver failure)
Increased capillary permeability (allergy, trauma)
Lymphatic obstruction
the plasma vs interstitial depends on balance of
oncotic and hydrostatic pressure
