How are the shapes of red blood cells and the shapes of nerve cells related to their functions? Thank you!

This biconcave shape allows the cells to flow smoothly through the narrowest blood vessels. Gas exchange with tissues occurs in capillaries, tiny blood vessels that are only as wide as one cell. Many RBCs are wider than capillaries, but their shape provides the needed flexibility to squeeze through.

                                Hope this helped you, have a good day bro cya)

i think it is true in my reasonment ..