21 8 Oefophagusy &f. [Book I. 



beginning from the bafe of the cranium and termi- 

 nating below in the celbphagus or gullet. Its fubftance 

 is merely mufcular, covered with the fame tender and 

 glandular membrane which lines the mouth, fauces, 

 and oefophagus. The ufe of the. pharynx is to receive 

 the aliment and impel it into the cefophagus. 



The cefophagus or gullet is a membranous tube, be- 

 ginning from the narrow termination of the pharynx. 

 It is placed between the vertebrae of the neck and the 

 windpipe, and defcending lower is embraced by the 

 pleura, and lies in a triangular fpace behind the me^ 

 diaftinum. Having arrived at the bottom of the tho- 

 rax it pailes through the left perforation of the dia- 

 phragm, and terminates in the cardia, or left orifice 

 of the ftomach. 



The cefophagus has four coats. Firft, a covering 

 from the pleura ; fecondly, a mufcular coat of con- 

 fiderable power ; thirdly, a cellular coat ; and laftly, 

 a tender internal coat, like that of the fauces, and 

 which is copioufly fupplied with mucus, * he cefo- 

 phagus conveys the food to the ftomach. 



The larynx is a hollow tube compofed of cartilages, 

 mufcles, and ligaments, fituated behind and below the 

 tongue, at the anterior part of the neck. The larynx 

 is conne6led above to the os hyoides, behind to the 

 root of the tongue and the pharynx. 



The cartilages of the larynx are the cricoid or an- 

 nular, which is narrow before and broad behind, and is 

 there divided mto two excavations, which receive the 

 ^.rytenoid cr pyramidal cartilages. The cricoid carti- 

 lage forms the bafis of the whole larynx. It is con- 

 nected below to the windpipe, and above to the pyra- 

 mid.il and thyroid cartilages. 



The thyroid cartilage relb perpendicularly on the 



cricoid, and conftitutes the upper, anterior, and largefl 



6 part 



