Question

multiple choice question
why do plasma proteins typically remain in the bloodstream and do not enter the tissue fluids?
o plasma proteins coat the lining of the endothelium and block the membrane pores.
o plasma proteins are too large to diffuse out of the capillaries.
o plasma proteins cannot pass through precapillary sphincters.
o plasma proteins are hydrophobic and so remain in the bloodstream.

Explanation:

Capillaries have small - sized pores. Plasma proteins are large - molecular - weight molecules. Due to their large size, they cannot easily diffuse through the capillary pores into the tissue fluids.

Answer:

Plasma proteins are too large to diffuse out of the capillaries.