Cannula n. : A small tube of metal, wood, or India rubber, used for various purposes, esp. for injecting or withdrawing fluids. It is usually associated with a trocar.

Example:
Nurses: Which way is the nasal Cannula supposed to go in?

Taxonomy
cannula, nasal cannula, cannulae, cannulation, vein, Intravenous cannula, free encyclopedia, Body piercing, plastic tubing, nose, Medicine, fluid, oxygen, blood samples, fistula, beat, blood pressure, Complications.

Defination from the web:
cannula may prevent this. ... A cannula is also used in an emergency procedure to relieve pressure and bloating in cattle due most commonly to their accidentally grazing ...