THE ORGANS OF DIGESTION 185 



Lies upon. Superficial Coverings. Below. 



Mylo-hyoid. Platysma. Tendon of 



Stylo-hyoid. Deep fascia. digastric. 



Hyo-glossus. Facial vein. 



Deep lobe : passes with duct between mylo-hyoid and hyo- 

 glossus. 



The duct of Wharton : passes with deep lobe of gland 

 beneath mylo-hyoid, resting on the hyo-glossns. At first the 

 lingual nerve lies above the duct and the hypoglossal nerve 

 below, but the duct, crossing over the nerve, passes up- 

 wards and forwards on genio-hyo-glossus to open on the 

 papilla by the side of the fraenum linguae. 



Nerves : sympathetic, and chorda tympani through sub- 

 maxillary ganglion. 



THE SUBLINGUAL GLAND occupies the sublingual fossa of 

 lower jaw, lying under mucous membrane of floor of mouth, 

 and having its anterior extremity close to the fraenum. Below 

 is the mylo-hyoid, and internally is the genio-hyo-glossus. 



Ducts of Rivini (18 to 20) : open separately in the floor of 

 the mouth. One larger one from the posterior part opens 

 into or by the side of Wharton's duct, and is called the duct 

 of Bartholin. 



Nerves : sympathetic, and from chorda tympani through 

 submaxillary ganglion. 



THE PHARYNX. 



The Pharynx is an oval musculo-membranous bag lying 

 behind the nose, mouth, and larynx. It is about 4^ inches 

 long, and extends from the base of the skull to the lower 

 border of the cricoid cartilage in front, and to the lower 

 border of the 5th cervical vertebra behind. It is widest 

 opposite the hyoid bone. Behind, it is separated by a pre- 

 vertebral layer of the deep cervical fascia from the longus 

 colli and rectus capitis anticus muscles of each side. Below, 

 it is continuous with the resophagus. 



A ttachments : 



Above : under surface of body of sphenoid, under surface 

 of petrous of temporal. 



In front: internal pterygoid plate, pterygo-maxillary liga- 

 me%. lower jaw, base of tongue, cornua of hyoid bone, and 

 styj \ hyoid ligament ; thyroid and cricoid cartilages, corre- 

 sponding to attachments of constrictor muscles. 



