Fluid exchange between capillaries and the interstitial fluid. takes place between the blood and interstitial fluid across the thin endothelial walls of the capillaries. blood pressure drives fluid out of the capillaries, blood proteins pull fluid back in the capillaries by osmotic pressure. Difference in osmotic pressure and blood pressure drives fluids out of capillaries at the arteriole end and into capillaries at the venule end.
Premarket approval (PMA) is the FDA process of scientific and regulatory review to evaluate the safety and effectiveness of Class III medical devices.remarket approval (PMA) is the FDA process of scientific and regulatory review to evaluate the safety and effectiveness of Class III medical devices.
Contrasted with the premarket notification process, the PMA (premarket approval) process is more rigorous because it requires a device sponsor to demonstrate that its device is safe and effective for its intended use, based on scientific evidence.lass III medical devices, or high-risk medical devices, are typically subject to the most stringent regulatory requirements, including the submission of a premarket approval application (âPMAâ).