Did you know these alternate names? 
1. Rennin is also called chymosin - involved in curdling of milk
2. Gastrin releasing peptide is also called bombesin
3. GIP - Gastric inhibitory peptide is also called Gluco-Insulinotropic Peptide (GIP) 

Did u also know -- 
Just as gastrocnemius/soleus is called 'peripheral heart', there is also peripheral brain or 'minibrain'.....what is it? Ans:- Enteric nervous system (ENS)