Question Regarding Kidney Function--particularly with last question

Let's assume that the potato chips are salty, it will cause Meghan to become dehydrated. Dehydration due to sweating, diarrhea, or excessive urine flow will cause an increase in osmolarity of the blood and a decrease in blood volume and blood pressure. As increased osmolarity is detected there is both a short and long-term effect. For the long-term effect, the hypothalamus sends a signal to the posterior pituitary to release antidiuretic hormone (ADH). ADH increases water reabsorption in the kidney. ADH promotes the reabsorption of water from the kidney by stimulating an increase in the number of water channels in the distal convoluted tubules and collecting tubules (ducts). These channels aid in the movement of water back into the capillaries, decreasing the osmolarity of the blood volume and therefore blood pressure.

A short-term effect of increased osmolarity is the excitation of the thirst center in the hypothalamus. The thirst center stimulates the individual to drink more water and thus
rehydrate the blood and extracellular fluid, restoring blood volume and therefore blood pressure.