1 8 HEAD AND NECK 



receive special names : they are the inferior labial, the superior 

 labial, the lateral nasal, and the angular continuation. 



The inferior labial (O.T. inferior coronary) arises below the 

 level of the angle of the mouth and passes towards the 

 median plane, under cover of the triangularis, the quadratus 

 labii inferioris, and the orbicularis oris. In the substance of 

 the lip it lies immediately adjacent to the mucous membrane, 

 and it anastomoses, in the median plane, with its fellow of the 

 opposite side. 



The superior labial arises about the level of the angle 

 of the mouth and runs medially in the upper lip, between 

 the orbicularis oris and the mucous membrane. Before it 

 anastomoses with its fellow of the opposite side, it gives off 

 a branch, the septal artery of the nose, which passes upwards 

 and ramifies on the lower and anterior part of the nasal septum, 

 where it anastomoses with the septal branch of the spheno- 

 palatine artery. 



The lateral nasal branch springs from the external 

 maxillary above the angle of the mouth. It ramifies on the 

 side of the nose and anastomoses, in the median plane, with 

 its fellow of the opposite side. 



The angular artery is the continuation of the external 

 maxillary beyond the point of origin of the lateral nasal 

 branch. It runs upwards in the substance of the angular 

 head of the quadratus labii superioris, and it terminates, at 

 the medial commissure of the eye, by anastomosing with the 

 dorsal nasal branch of the ophthalmic artery. 



In addition to the branches already noted, a very definite 

 branch is usually given off from the anterior aspect of the 

 external maxillary artery immediately after it crosses the 

 lower border of the mandible. This branch (O.T. inferior 

 labial) runs towards the median plane under cover of the 

 triangularis and the quadratus labii inferioris, and it anasto- 

 moses not only with the inferior labial (O.T. inferior coronary) 

 above, and its fellow of the opposite side in the median plane, 

 but also with the mental branch of the inferior alveolar artery. 



The Terminal Branches of the Facial Nerve. The dis- 

 sector should note that there are five terminal branches, or 

 groups of branches, of the facial nerve : (i) temporal ; (2) 

 zygomatic ; (3) buccal ; (4) mandibular; (5) cervical. They 

 all emerge from under cover of the parotid gland, the 

 temporal branches at its upper end, the cervical at its lower 



