DEGLUTITION 



177 



movements of the tongue, however, will be described farther on in con- 

 nection with the mechanism of the first period of deglutition. 



The pharynx, in which the most complex of the movements of deglu- 

 tition take place, is an irregularly funnel-shaped cavity, its longest 

 diameter being transverse and opposite the cornua of the hyoid bone, 

 with its smallest portion at the opening into the oesophagus. Its length 



'17 



35- Muscles of the pharynx (Sappey). 



i, 2, 3, 4, 4, superior constrictor; 5, 6, 7, 8, middle constrictor; 9, 10, n, 12, inferior constrictor; 

 13, 13, stylo-pharyngeus ; 14, stylo-hyoid muscle ; 15, stylo-glossus ; 16, hyo-glossus ; 17, mylo-hyoid 

 muscle ; 18, buccinator muscle ; 19, tensor palati ; 20, levator palati. 



is about four and a half inches (11.43 centimeters). It is connected 

 superiorly and posteriorly with the basilar process of the occipital bone 

 and with the upper cervical vertebrae. It is incompletely separated 

 from the cavity of the mouth by the velum pendulum palati, a movable 

 musculo-membranous fold continuous with the roof of the mouth and 

 marked by a line in the centre, which indicates its original develop- 

 ment by two lateral halves. This, which is called the soft palate, when 



