Which sequence best describes a normal route for the flow of tears from the eyes into the nasal cavity? a. lacrimal canaliculi, lacrimal sacs, nasolacrimal ducts; lb. acrimal ducts, lacrimal canaliculi, nasolacrimal ducts; c. nasolacrimal ducts, lacrimal canaliculi, lacrimal sacs.

Video transcript

Hi, everybody. Here's our next question. It says the structure that connects the lacrimal sax to the nasal cavity is a lacrimal canaliculi b, lacrimal sac C nasal lacrimal duct or D trigeminal nerve. Well, you got one you can eliminate right away because we're looking for something that connects lacrimal sacks to the nasal cavity. So try to be lacrimal sack is not going to be our answer as that's one of the things that's supposed to connect. So we can eliminate that right away. Choice D is pretty easily eliminated. Trigeminal nerve, a nerve. You wouldn't usually describe the structure connecting something. And indeed that trigeminal nerve is a facial nerve involved in things like uh sensation. Yeah, motor control and chewing. It kind of goes under motor control. So now we've got two possibilities for this structure, the lacrimal canaliculi and the nasal lacrimal duct. Well, we've got a clue right in the name because we're looking for something that connects the lacrimal sac and the nasal cavity. So naso lacrimal duct right there has both things in its name and that is indeed the structure that we are looking for and that nasal lacrimal duct is a narrow tube that collects tears and goes from that sack and then goes into the nasal cavity. As our question says, finally, we look at the lacrimal canaliculi and this is a small channel that drains tears from the eye at the surface and then drains them to the lacrimal sac. So again, the structure that then connects the lacrimal sac to the nasal cavity is choice c the nasal lacrimal duct. See you in the next video.