Smell. 473 



nect with the cavities in the ethmoid bone. There is also an opening in 

 the upper jaw bone on each side called the Antrum of Highmore, and 

 these are connected with the ethmoid cavities and the large cavities of 

 the nose. Besides these are the lachrymal passages leading from the 

 nasal passages to the tear glands ; and lastly the pharynx is reached 

 from all these cavities through the rear doors of the nasal openings, and 

 from that, access may be had with the cavity of the mouth and the eu- 

 stachian tubes leading up to the ears. The walls and projections of all 



FIG. 217. Vertical Cross-section of Nose from base of 

 brain to the palate. 



Cr. Cribriform bone on which the base of the brain 

 rests. 



PL Palate. 



&p. Septum or cartilaginous partition between the 

 two cavities. 



6' T,MT,I T Superior, Middle and Inferior Turbinal 

 Bones. 



An. Antrum; Cavity in Upper Jaw Bone. 



The olfactory nerve filaments are distributed to the sur- 

 face of the septum and upper two turbinal bones. 



FIG. 217. 



these openings are covered with this epithelium. The cavities on the 

 two sides of the nose do not directly connect with each other, being sepa- 

 rated by a cartilaginous wall or septum. The back or upper part of each 

 of the nasal cavities is divided into three passages ( meatus ) by three 

 scroll-shaped bones called the turbinated bones ( from turbo, a top ). 

 These are placed one above another, attached to the outer side of the 

 cavity and presenting a convex side toward the median septum. 



FIG. 218. FIG. 219. 



FIG. 218. Vertical section of right nasal cavity showing its outer wall. 



FIG. 219. Inner wall of the left nasal cavity or left side of the middle partition of the 

 nose; references same in both. 



PI. Palate roof of the mouth. 



V V V V Branches of the Fifth nerve or Trigeminum. 



1. The Olfactory nerve lying on top of the cribriform or ethmoid bone through holes 

 in which the numerous branches pass to the nasal cavities. 



tit , Mt, It Superior, Middle and Inferior Turbinal Bones. 



The part of the epithelium which lines the nasal cavities is called the 

 pituitary membrane and sometimes the Schneiderian membrane. The 

 part of this membrane which covers the middle and upper turbinated 

 bones is the portion which, in man, is differentiated into the organ of 



