298 SPLANCHNOLOGY. 



HYO-PHARYNGEUS. 



(Fie. 90. n.) 



This is a flat muscle arising from the heel process of the hyoid 

 bone, and slightly from the thyoid cartilage of the larynx. Its 

 fibres passing upwards and backwards, it reaches its fellow of the 

 opposite side at the posterior median line. It is a constrictor. 



THYRO-PHARYNGEUS. 



(Fio. 90. o.) 



Placed immediately below the muscle last described, this 

 muscle joins its fellow in a similar manner, arising from the 

 thyroid cartilage. It also is a constrictor. 



CRICO-PHARYNGEUS. 

 (Fie. 90. p.) 



Situated below the thyro-pharyngeus, this muscle arises from 

 the lateral aspect of the cricoid cartilage. Its fibres run back- 

 wards, converging slightly upwards, and it terminates similarly 

 to the two muscles last described, its action resembling theirs. 



ARYTENO-PHARYNGEUS. 



This is a small band stretching from the posterior aspect of 

 the arytenoid cartilage to the muscular wall of the oesophagus, 

 its action being to raise the latter. 



The pharynx is supplied with blood by the pharyngeal and 

 thyro-laryngeal arteries. Its nerves are derived from the ninth 

 and tenth pairs, and from the sympathetic. Its respiratory 

 function is purely a passive one, while what may be termed its 

 alimentary function is an active one, to assist in deglutition. 



(ESOPHAGUS. 



The oesophagus, or gullet, is a long musculo-membranous 

 cylindrical canal, passing from the pharynx to the stomach, 

 through which the food reaches the latter. Originating at the 

 lower part of the pharynx, immediately behind the aperture of 

 the larynx, it descends the neck, at first behind the trachea, then 

 inclines to the left of it, the two entering the thorax together ; it 



