Cardio Microcirculation Flashcards
What is the function of microcirculation
Regulation of blood volume by altering the distribution of fluid between interstitial and vascular compartents.
And to exchange molecules from the blood to cells and vice versa
Where are precapillary sphincters located and what do they do?
They constrict or activate to regulate flow. They are located where the arterioles lead into capillary beds.
Do capillaries have smooth muscle cells
No
what substances freely diffuse through the3 capillary wall?
Co2 and O2, These substances are labeled as lipophilic b/c they are able to pass through the cell wall.
What is reflection coefficient
A value that describes the permeability of a solute. 1 means totally reflected/impermeable
0= totally permeable.
When would the reflection coefficient for protein not be close to 1
During times of increased capillary permeability such as inflammation and burns
What is the starling equation and what is it telling us
Tells us what factors affect filtration. It is
Flow= Filtration coefficient [ (Capillary hydrostatic pressure - interstitial hydro pressure) - (capillary oncotic- interstitial oncotic)]
What contribiutes to the filtration coefficient
pr-capillary sphincter (the degree to which it shunts flow around capillary beds), the type of capillary (fenestrated vs. continuous, fnestrated is more permeable), and inflammation
What does interstitial hydrostatic pressure depend on?
Interstitial fluid volume which depends on the filtrate flowiong in from the capillaries and the lymph flowing out
Interstitial oncotic pressure determined by
ALbumin which can be decreased in liver disease, starvation, kidney disease, or dilution by IV fluids
Causes of edema
increased capillary pressure, increased interstitial pressure, increased plasma oncotic pressure, increased interstitial oncotic pressure, increased permeability
