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ANATOMY AND PHYSIOLOGY 



column, to pass into the thorax. It finally comes forward in 

 front of the aorta, passes through the diaphragm, and terminates 

 in the stomach. It is a tube about nine inches long, having two 

 layers of muscles (circular within, longitudinal without) and lined 



JJ 



FIG. 103. SHOWING SITUATION OF PHARYNX BEHIND NOSE, MOUTH, AND LARYNX 



(From Dealer's "Surgical Anatomy .") 



a,~b, c, dj e, Turbinal bones and meatuses of the nose; g.i, tongue; h, posterior 

 palatine arch; y, anterior palatine arch; k, hyoid bone;.;, mylo-hyoid muscle (floor of 

 mouth); m, thyro-hyoid membrane; n, ventricle of larynx; p, q. r, sphenoid bone and 

 sphenoidal sinus; v, hard palate; w, soft palate; x, uvula; z, tonsil; t, naso-pharynx; u, 

 orifice of auditory tube; aa, oro-pharynx; dd, laryngo-pharynx; bb, epiglottis; ee, 

 upper portion of larynx; gg, vocal bands; /, false vocal bands; hh, lower part of 

 larynx; ii, cricoid cartilage; jj, trachea. 



with mucous membrane. By contraction of the different muscles 

 from above downward the food is passed along to the stomach. 



The esophagus lies at first immediately behind the trachea. 

 The upper part is composed of striated, or voluntary muscle like 

 that of the pharynx; in the lower part the muscle is non-striated, 

 or involuntary, like the stomach. 



