Cannula

A smooth, blunt-ended tube inserted into a blood vessel, lymphatic vessel, or body cavity, in order to introduce or withdraw fluids. Cannulas are used for blood transfusions and intravenous infusions and for draining pleural effusions. They may be left in place for several days if continuous testing of, or introduction of, fluids is required.

 

Online Medical Dictionary: Your essential reference to over 5000 medical terms.