34 OUTLINES OF ANATOMY. 



Lymphatics from the temporal and zygomatic fossae, 691. (676) 



The structures in the submaxillary or supra-hyoid triangle will now be exposed. Divide the facial 

 artery and vein where they cross the mandible. Draw the tongue forward and stitch it to the nose. 

 Divide the anterior belly of the digastric at its origin from the mandible and throw it back, exposing 

 the mylo-hyoid. 



Submaxillary or Supra-hyoid region. 



Submaxillary lymphatic glands, 690. (675) 



Supra-hyoid. 



Lingual-glands, 692. (677) 

 Mylo-hyoid, 479~8o. (472-3) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. Variations. 



Divide the mylo-hyoid at its origin, beginning at the outer border; reflect the muscle inward and 

 downward to the insertion, detaching it along the median raphe. With the saw, divide the mandible 

 about a quarter of an inch external to the symphysis. Tilt the lateral portion of the mandible upward 

 from the lower border and retain it in that position while the structures of the region are being exposed. 

 Care must be used not to injure the mucous membrane of the floor of the mouth. The submaxillary 

 gland is now exposed, with the surrounding muscles and the structures crossing them. The submandi- 

 bular ganglion lies between the submaxillary gland and the hyo-glossus muscle ; it can be readily ex- 

 posed by carefully turning down the gland from its upper border and following the chorda tympani and 

 the branches of the lingual nerve passing to it. The stylo-glossus, hyo glossus, and genio-hyoid 

 muscles will be exposed, also the anterior portion of the genio-hyo-glossus. 



Submaxillary gland, 984. (963) 



Duct of the submaxillary gland. 



Arteries. 



Nerves. 

 Sublingual gland, 984-5. (963) 



Duct of Rivini. 



Arteries. 



Nerves. 

 Lingual nerve, 8045. (786) 



Branches. 

 Submandtbular ganglion, 805. (787) 



Branches. 

 Hypoglossal nerve, 8212. (802) 



Nerve to the genio-hyoid. 



True hypoglossal branches : 

 Nerve to the stylo-hyoid. 

 Nerves to the hyo-glossus. 

 Nerves to the genio-hyo-glossus. 

 Stylo-glossus, 482-3. (474-5) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 

 Hyo-glossus, 481-2. (474) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 

 Genio-hyoid, 480. (473) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. Variations. 



Divide the hyo-glossus at its origin ; carefully separate it from the subjacent structures ; draw it from 

 under the structures crossing its surface; throw it upward and expose the structures beneath it. 



Lingual artery, 513-14-15. (505-6) 

 Second part of its course. 

 Third part of its course. 

 Branches : Dorsalis linguae. 



Sublingual artery : 



Artery of the fraenum. 

 Ranine artery. 

 Lingual vein, 665-6. (652) 

 Genio-hyo-glossus, 481. (473-4) 



Origin. Insertion. Structure. Nerve-supply. Action. Relations. 



Divide the posterior belly of the digastric at its origin and throw it downward ; in raising the muscle 

 note the branch of the facial nerve which supplies it, also the branch to the stylo-hyoid. Divide the 



