Choana; Posterior nasal aperture - Choana; Apertura nasalis posterior
Choana is the posterior nasal aperture.The choanae are separated by the vomer. Choana is a space bounded as follows: anteriorly and inferiorly by the horizontal plate of palatine bone, superiorly and posteriorly by the sphenoid bone laterally by the medial pterygoid plates.
This definition incorporates text from the wikipedia website - Wikipedia: The free encyclopedia. (2004, July 22). FL: Wikimedia Foundation, Inc. Retrieved August 10, 2004, from http://www.wikipedia.org
General Anatomy > Bones; Skeletal system > Axial skeleton > Cranium > Bony nasal cavity > Choana; Posterior nasal aperture