the following structures open into the middel meatus the following structures open into the middel meatus: a- nasolacrimal duct b- posteror ethmoidal sinus c- maxillary sinus d- sphenoid sinus e- anterior ethmoidal sinus 1- a,b &d 2- a & b ***3- c & e 4- all of the above Share This: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook