Definition and Illustration:
hypertension (Greek hyper = about, tonos = voltage) describes the tonic relationship between two fluids, where the osmotic pressure in the outer medium is lower than in the inner medium. The number of dissolved particles in both liquids are accordingly different. In the cell interior are more, in the outer medium less, dissolved particles.
As a result, the cell fluid flows out of the cell until the osmotic pressure returns to an isotonic level on both sides of the semipermeable membrane.
Note: The term hypertension is used in the medical terminology for increased blood pressure, but has nothing to do with the term hypertension in relation to tonicity.