4b73950a_all_the_bones__notes
[feature] ethmoidal air cells [bone] ethmoid [description] pneumatized spaces (3-18 in number) within the ethmoid bone; located between the orbits [notes] 
three groups may be identified: anterior (drain into the hiatus semilunaris in the middle nasal meatus); middle (drain onto the apex of the bulla ethmoidalis in the middle nasal meatus); posterior (drain into the superior nasal meatus)
all the bones
notes