THE PHARYNX 405 
divisible into two parts. It presents for description two surfaces, two borders, and 
two extremities. The lateral surface is covered by the parotid gland, the occipito- 
mandibularis, digastricus, and pterygoideus medialis muscles. The tendon of the 
sterno-cephalicus crosses this surface, and, together with the aponeurosis connect- 
ing it with that of the brachiocephalicus, is a useful guide in separating the parotid 
gland from it. The medial surface is related to the rectus capitis ventralis major, 
the guttural pouch, the larynx, the division of the carotid artery, and the tenth, 
eleventh, and sympathetic nerves. The dorsal border is concave and thin. It 
is related to the guttural pouch and the duct of the gland. The ventral border 
is convex and thicker. It is related to the external maxillary vein and often to 
the thyroid gland. The posterior extremity is loosely attached in the fossa atlantis. 
The anterior extremity lies at the side of the root of the tongue, and is crossed 
laterally by the external maxillary artery. The mandibular or submaxillary duct 
(Ductus mandibularis s. submaxillaris)' is formed by the union of smali radicles 
which emerge along the concave edge. It runs forward along this border, and, after 
leaving the anterior extremity, crosses the termediate tendon of the digastricus, 
passes between the hyo-glossus and mylo-hyoideus, and gains the medial surface 
of the sublingual gland. Its terminal part lies on the body of the mandible, under 
the mucous membrane, which it pierces opposite the canine tooth. The orifice is 
at the end of a flattened papilla, the caruncula sublingualis. The gland differs 
in finer structure from the parotid in possessing serous, mucous, and mixed 
alveoli. 
Blood-supply.— Occipital, external carotid, and external maxillary arteries. 
Nerve-supply.—Chorda tympani and sympathetic nerves. 
The sublingual gland (Glandula sublingualis) (Figs. 330, 561) is situated be- 
neath the mucous membrane of the mouth, between the body of the tongue and the 
ramus of the mandible. It extends from the symphysis to the third or fourth 
lower cheek tooth. Its length is about five or six inches (ca. 12 to 15 em.) and its 
weight about half an ounce (ca. 15 to 16 g.). It is flattened laterally, and has a 
thin dorsal border which underlies the sublingual fold of the mucous membrane 
of the floor of the mouth. The lateral surface is related to the mylo-hyoideus 
muscle, and the medial surface to the genio-glossus and stylo-glossus, the mandib- 
ular duct, and branches of the lingual nerve. The ventral border is related to 
the geniohyoid muscle. The sublingual ducts (Ductus sublinguales), about thirty 
in number, are small, short, and twisted; they open on small papillz on the sub- 
Imgual fold. The gland has mixed alveoli. 
Blood-supply.—Sublingual artery. 
Nerve-supply.—Trigeminal and sympathetic nerves. 
THE PHARYNX 
The pharynx is a musculo-membranous sac which belongs to the digestive and 
respiratory tracts in common. It is somewhat funnel-shaped, the large anterior 
part joining the mouth and nasal cavity, while the small end is continued by the 
cesophagus. Its long axis is directed obliquely downward and backward, and has 
a length of about six inches (ca. 15 em.). The pharynx is attached by its muscles 
to the palatine, pterygoid, and hyoid bones, and to the cricoid and thyroid cartilages 
of the larynx. 
Its principal relations are: dorsally, the base of the cranium and the guttural 
pouches; ventrally, the larynx; laterally, the medial pteryoid muscle, the great 
cornu of the hyoid bone, the external carotid and external maxillary arteries, the 
1 Formerly known as Wharton’s duct. 
