1. Substance A is commonly consumed by American adults. In addition to a variety of other physiological effects, substance A binds to and inhibits/blocks the opening of voltage gated Ca2+ channels in the hypothalamic neurons that release ADH at the posterior pituitary. Predict the effect that consumption of substance A will have on the following variables. Below each – clearly explain the cellular mechanism behind your answer (24 pts) 1. Water reabsorption by the nephron: 2. Sodium reabsorption by the collecting duct: 3. Urine Volume and Osmolarity (concentration):