Microcirculation Flashcards
What is the term we use to define a terminal arteriole?
Metarteriole
What is the purpose of the pre-capillary sphincter?
It is the site for changing blood flow by constricting or relaxing the sphincter
What is the function of slit pores?
Determine what is able to pass (mostly water and soluble substances) through the capillary bed into the interstitial fluid
Why does the liver have loose endothelial cells verses the brain that has tight endothelial pores?
The liver needs to filter plasma proteins thus the pores must be larger than the brain which has tight junctions (think BBB)
What regulates vasomotion?
The vessels intermittently contract and relax as a response to O2 levels
How does water and nutrients move in the interstitium?
Water and nutrients move by diffusion the do NOT flow, thus the delivery of nutrients to the tissues is dependent on a concentration gradient
Why is interstitial fluid pressure considered sub-atmospheric?
Thought to be a result of the lymphatic system, generates a negative pressure
There is a net fluid movement out of the capillary, why dent we have fluid build up in the tissues?
The venous capillaries are more numerous and more permeable and the lymphatics
What factors might increase ISF pressure?
Increased cap pressure/permeability
Increase ISF oncotic pressure
Decreased plasma oncotic pressure
How does the lymph circulate back to the vena cava if it doesn’t have a pump?
Skeletal muscle movement is the pump
What is the result of an exhausted lymph system?
Edema
