Canula
Latin for channel; medically any semi-permanent arrangement giving access to the bloodstream. The wide hollow needles used, of which the best known brand are Medicuts, are also used for permanent piercing
Catheter - catheterization
Cath. Flexible tube used in medical treatment and surgery for feeding into various body structures to allow access from the outside. In SM most likely to mean those catheters designed for the bladder, often utilized in SM 'control scenes: the best type to use for this purpose is the foley catheter, which has a balloon that can be inflated with sterile water to hold it in place once inserted.
I never imagined these items used in scenes until I read these descriptions. So my virgin imagination is going wild. Has anyone ever used either of these in name scene? Ever witnessed it. Thoughts? Feelings?