454 Anatomy Appliea to Medicine and Surgery. 



branches of the fifth nerve to its centre in the medulla, 

 which communicates with the nucleus of origin of the 

 pneumogastric. 



In Fracture of the nasal bones, it is well to remem- 

 ber, that there is a space of about one-sixth of an inch, 

 only, in width at the roof of the nasal fossae, so that, when 

 ussing any instrument to replace the fractured bones, it 

 should not be larger than this; in fact, it is desirable 

 to employ even a smaller one, since the swollen mucous 

 membrane would lessen the normal width of this space. 

 Any larger sized instrument would impinge on the nasal 

 process of the superior maxillary bone without coming in 

 contact with the nasal bones at all. The posterior narial 

 orifice, which is about one inch by half an inch in size, 

 may require to be plugged in persistent epistaxis, and, 

 when this operation is necessary, the plug should be a 

 little larger than the dimensions of this orifice. A rough 

 index to the dimensions of the plug required for plug- 

 ging the posterior nares, is found in the size of the distal 

 phalanx of the thumb. 



The Mouth The lips are composed, from before 

 backwards, of integument, superficial fascia, orbicularis 

 oris muscle, submucous tissue and mucous membrane. 

 The inferior and the superior coronary arteries, along 

 with the branches of the infraorbital and mental nerves 

 that supply the lips with sensation, are found in the sub- 

 mucous tissue, and, since the lips are richly supplied with 

 blood, wounds of their substance heal rapidly. The lym- 

 phatics of the central part of the lower lip converge to a 

 gland above the hyoid bone, while those from the lateral 

 aspects of this lip, along with the lymphatics from the up- 

 per lip, go to the submaxillary and the superior deep cer- 

 vical glands. In hare-lip the defect does not occupy the 

 median line, since the middle portion of the lip, along with 



