Which valve is present at opening of nasolacrimal duct-
Ans. is 'a' i.e., Hasner's valve o Nasolacrimal duct opens into inferior meatus and is closed by a mucosal flap called Hasner's valve,o Heister valve (spiral valve) is present in cyclic duct.
Hasner's valve
Heister valve
Spiral valve
None
Nose