Some isotopes are radioactive, which makes them suitable for medical imaging procedures. Radioactive isotopes have found a wide range of use in medicine. For example, they are used as tracers for diagnostic as well as research on metabolic processes. They are also used in medical imaging procedures, these isotopes include fluorine-18, gallium-67 among many others.
The limbic cortex. Another area called the precuneus also plays a role.
Not 100% sure here but from what I remember I think it is called osmosis... It is if the water is leaving or entering the cell.
