What is the name of the tear drainage channel that extends from the lacrimal sac to the opening in the mucous membrane of the nose?

Canaliculi is the tear drainage channel that extends from the lacrimal sac to the opening in the mucous membrane of the nose.

Canaliculi is the tiny channel in each eyelid that forms part of the tear drainage system. The passage is called canaliculus. Several small ducts in the eye is lacrimal canaliculi.

the answer is:

carbon dioxide