Final answer:
Seawater cannot be consumed because it is hypertonic to your cells. Drinking saltwater draws water out of your cells, making you thirstier. Our bodies cope better with hypotonic solutions, where excess water is excreted by the kidneys.
Step-by-step explanation:
Seawater cannot be consumed because it is hypertonic to your cells. The osmolarity of seawater is about three times higher than most bodily fluids. When you drink saltwater, water from your cells is drawn out to dilute the high salt concentration, which actually makes you thirstier. Our bodies cope better with hypotonic solutions, where excess water is collected by the kidneys and excreted.