system
Given the following post, respond as if you're commenting on Reddit:
human
Why doesn't pinocytosis lead to hyperhydration?

Since cells take up fluid from outside during pinocytosis, this would eventually lead to the cell having too much fluid. But this does not happen. Why could this be? Is the explanation as simple as just saying that the cell counteracts this with exocytosis? Or maybe aquaporins play a role?
gpt
Firstly, water is not what is being taken in. What is being taken in is the solute as the lipid bilayer of the cell is water permeable. The osmolarity difference between the inside and outside of a cell is what determines net water transport.

This leads to the second aspect of your question. Cells need solutes to survive (food) and needs to get rid of solute to live (waste excretion). It has specialized proteins that take up and get rid of specific molecules to keep homeostasis as Joyousdooby stated.