Final answer:
ORT solutions contain table salt to replenish electrolytes and prevent the dangerous swelling of cells caused by drinking excessive water, ensuring the proper balance of fluids across cell membranes.
Step-by-step explanation:
Oral rehydration therapy (ORT) solutions contain a small amount of table salt (NaCl) because sodium helps to replenish electrolytes lost through sweat, vomiting, or diarrhea. This is crucial to prevent hyponatremia, a condition of low sodium concentration in the blood caused by drinking excessive amounts of water without replenishing electrolytes. Sodium in ORT solutions helps maintain the balance of fluids in and out of cells through osmotic pressure, thereby preventing the cells from swelling, a dangerous condition known as water intoxication. Osmotic pressure ensures that water does not move excessively into cells, which would cause them to swell and potentially burst, leading to serious health issues or death.
In summary, the inclusion of table salt (NaCl) in ORT solutions aids in maintaining a proper osmotic balance within the body's fluid compartments, ensuring the correct function of brain, muscle, and heart cells and preventing water intoxication.