SPLANCHNOLOGY. 185 



isilimus faucium^ is bounded above by the velum and uvula, below by the 

 tongue, on each side by the arches of the palate. 



The anterior part of the palate, or hard palate^ is formed of the palate 

 plates of the maxillary and palate bones, covered by mucous membrane 

 and glands ; the posterior part of the palate, or sofi palate^ or velum pendu- 

 lum^ consists of a dense aponeurosis, and of several muscles and glands, 

 inclosed in mucous membrane. 



The cheeks are formed of mucous membrane, covered by the buccinator 

 and a quantity of fat ; several small mucous glands lie between the mem- 

 brane and this muscle, and towards the upper and back part on each side 

 we perceive the small opening of Steno's duct. 



The lips are composed of integuments with more or less of fat, muscles, 

 vessels, nerves, glands, and mucous membrane. The skin is delicate and 

 vascular, particularly at the red borders, where it is continuous with the 

 mucous membrane of the mouth. The cuticle is continued over the latter 

 to line the whole cavity as a very fine epithelium. The muscles are, the 

 orbicularis oris, with which the fibres of many others (already described) 

 intermingle. The arteries of the lips are the coronary vessels, assisted by 

 their inosculations with branches of the internal maxillary artery. The 

 sentient nerves are derived from the infra-orbital and dental branches of 

 the fifth, and the motor from the seventh pair. The labial glands are very 

 numerous ; they are rounded and pale, and are situated in the submucous, 

 loose cellular tissue, at some distance from the red border. The mucous 

 membrane is continued from each lip to the alveolar processes of the 

 maxillae, and forms in the centre of each a small fold or fra?num ; this is 

 larger in the upper than in the lower lip. 



The mouth is lined throughout by mucous membrane, which is continu- 

 ous with the cutis on the lips, and extends posteriorly through the pharynx, 

 whence it ascends to line the nares, the Eustachian tube, and tympanum, 

 on each side, and descends to line the oesophagus and larynx ; it is also 

 continued into the ducts of the sublingual, submaxillary, and parotid glands ; 

 as it is reflected from one surface to another, it forms folds or fraena, as 

 between the lips and alveoli and beneath the tongue ; at the sides of the 

 fauces, also, it forms two semilunar folds on each side, called the pillars or 

 arches of the palate ; these folds inclose muscular fibres, which we shall 

 examine afterwards. 



On looking into the mouth, either in the living or dead subject, the 

 following objects strike the attention : inferiorly, the tongue and inferior 

 teeth ; laterally, the cheeks ; posteriorly, the back part of the pharynx ; 

 superiorly, the superior teeth, the hard and soft palate, from the centre of 

 the latter the uvula, and from the sides, the pillars or arches descending to 

 the tongue and pharynx ; in the recess between these pillars on each side, 

 the tonsils or amygdala are also seen ; lastly, if the tongue be drawn forward, 

 the epiglottis comes into view. 



PI. 129, fig. 30, cavity of the mouth: ', palate ; ", velum palati; ', uvula ; 

 *, arch of the palate to the mucous membrane of the pharynx ; ', arch to the 

 tongue: °, tonsil; ', tongue; ", epiglottis, aad beneath this the pharynx 



891 



