What's the difference between i.e. and e.g.?
cannula can·nu·la or can·u·la (kān'yə-lə)
n. pl. can·nu·las or can·nu·lae (-lē')
A flexible tube, usually containing a trocar at one end, that is inserted into a bodily cavity, duct, or vessel to drain fluid or administer a substance such as a medication.