Venom is a modified saliva. It is produced in the venom gland, travels through the venom duct, and injected by means of the hollow moveable teeth called fangs.
Snakes are venomous, they are not poisonous. Venom is injected, poison is ingested or infused.
Click on FRED the albino eastern diamondback rattlesnake for the next page in the site tour. :-)