Salivation
Seeing a plate of food triggers the secretion of saliva in the mouth and the production of hydrochloric acid in the stomach.
Source
Boundless vets and curates high-quality, openly licensed content from around the Internet. This particular resource used the following sources:
"OpenStax College, Digestive System Regulation. October 17, 2013."
http://cnx.org/content/m44744/latest/Figure_34_04_01.jpg
OpenStax CNX
CC BY 3.0.
