Sometimes while traveling, people are infected with a protist parasite, Giardia. One of the side effects of Giardia infection is
diarrhea. When someone has diarrhea, they lose excessive water and salt from the body. The result is loss of Na+, dehydration that leads to decreased extracellular volume and plasma volume, and decreased arterial blood pressure. Given this would the vasopressin secretion of a person infected with Giardia:increasedecrease
Vasopressin is ADH. ADH is secreted by the hypothalamus and regulates the body's osmolarity. Since Giardia causes a loss of sodium ions, the body's osmolarity is affected. To counteract this and maintain homeostasis, more vasopressin is secreted, thus telling the body to absorb more ions back in the kidneys.