Answer:
angiotensin II and aldosterone
Why does absorption occur in the small intestine?
The small intestine makes up a significant portion of the digestive tract, the food must be sufficiently digested to break down into molecules that the body can actually absorb, and the medial small intestine has a specialized structure (microvilli) that increases surface area for the purpose of absorption.
This is not meant to imply that all absorption happens in the small intestine, since that is untrue, or that all absorption that matters happens there as well, as that would also be untrue.
Thank you,
Eddie