Final answer:
We do not swell and pop when swimming because our body regulatory mechanisms handle hypotonic solutions, with the skin acting as a barrier and the kidneys excreting excess water, maintaining cellular homeostasis.
Step-by-step explanation:
When we go swimming, our cells do not swell and pop because our body has mechanisms to regulate osmolarity and handle hypotonic solutions, such as the water in swimming pools. Our skin acts as a barrier, preventing excessive water from entering our body.
Additionally, any excess water that does enter our body through our mouth or other means is collected by our kidneys and excreted. This is unlike the process where red blood cells placed in a hypotonic solution may undergo hemolysis, or bursting, due to the influx of water.
Our body is adapted to ensure that neither cellular lysis (rupture) nor severe edema occurs under normal circumstances such as swimming in a pool.
Moreover, our bodies maintain a careful balance of water and solute concentrations. In cases of hypo- or hypertonic environments, cellular functions may be compromised, leading to deterioration of the cells if the situation is not handled appropriately.
But the body's regulatory systems, including the secretion of excess water and salts, allow us to maintain stable internal conditions, preventing damage from hypo-osmolarity in environments such as a swimming pool.