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APPLIED PHYSIOLOGY 



irritate the nerves in the mouth and so blunt the taste for 

 good food. For this reason a drinker does not enjoy plain 

 food, but requires spices to excite his taste. 



591. The nose. Impressions of smell originate within 

 the nose. Each nostril leads to a wedge-shaped cavity, 



The outer wall of the nose. 



a the nerve of smell at the base of the 



brain. 



b air spaces in the skull bones. 

 c branches of the nerve of smell. 



d curved curtains of bone. 



e opening of the Eustachian tube. 



/ soft palate. 



g upper jawbone. 



which opens into the pharynx. The inner wall of each 

 cavity is smooth, and is formed by the thin bone that 

 separates the two nostrils. Each outer wall is formed by 

 three very thin bones which hang down like narrow cur- 

 tains. They nearly cover cavities, called sinuses, which 

 are situated in the neighboring bones. One sinus occupies 

 the interior of the upper jawbone, and is called the antrum. 

 The part of the skull behind the eyebrows is honeycombed 

 with small cavities, called the frontal sinuses. 



