The presences of myelin allows an axon to conduct their signals rapidly
"A nephron is used to separate water, ions, and small molecules from the blood, filter out wastes and toxins, and return needed molecules to the blood."
https://biologydictionary.net/nephron/
I believe a valley or mountain, but I am not 100 percent sure.
Blood pressure
This is indicated in Starling's Hypothesis in which there is fluid movement due to filtration across the wall of capillary. This is dependent between hydrostatic pressure gradient and oncotic pressure across the capillary. The balance of these forces allow the net driving pressure for filtration. The net fluid influc is proportional to this net driving pressure. The leakage of proteins across the capillary membrane has important effects and has corresponding cause in the balance of forces.
