THE NOSE 



893 



The vessels. — The arteries of the nose which arise from the facial are the 

 lateralis nasi and tlie artery to the septum derived from the coronary of the same 

 trunk. This latter also supplies the ala. The nasal branch of the ophthalmic 

 and infraorbital are distributed to the sides and dorsum. 



The veins terminate by joining the facial and ophthalmic. 



The nerves. — The nerves are sup])lied by the facial, which is motory, and by 

 the infratrochlear and nasal branch of the ophthalmic division of the fifth and the 

 infraorljital nerve, which are sensory. 



The nasal fossae. — The nasal fossae have been already described (page 79). 



The mucous membrane (pituitary or Schneiderian). — In the recent state the 

 area of the fossie is much contracted l)y its mucous lining. This is loosely folded 

 around the lower edges of the turl)inal bones, and extends beyond them in front 

 and behind. Especially is this marked where it envelops the inferior turbinal 

 bone, and it is here very thick and spongy. It is, moreover, thick where it covers 

 the septum, but thin at the bottom of the meatuses and within the sinuses. 



Fjg. olG.— Muscles of the Nose. (After Bourgerj-.) 



i 



Levator labii superioris 

 alseque nasi 



Accessory slip of compressor 

 naris 



Dilator naris posterior 



Orbicularis oris 



Oceipito-lrontalis 



Fyramidalis nasi 



Compressor naris 



\^^ Dilator naris anterior 



i^— ^^ — Compressor narium minor 



Some of the openings into the nasal cavities which are apparent in the dried skull 

 are quite hidden in the recent state; those, however, which lead into the air-spaces 

 together with the lachrymal duct remain patent, though the bony orifices are mucli 

 reduced in size. There is a small conical closed sac, close to the septum at its 

 fore part, which indicates the position of the now obliterated canal of 8tenson. 

 The termination is marked in the mouth by the incisive pajiilla. The membrane 

 is continuous in front through the anterior nares with the skin; behind, it extends 

 through the posterior nares to line the naso-pharynx, the Eustachian tube, the 

 tympanum and the mastoid cells. It is intimately adherent to the periosteum and 

 perichondrium. The acinous glands which are imbedded in its structure secrete 

 for the most j)art a thin wateiy fluid. They are especially large over the inferior 

 turbinal bone, and very numerous at the middle and back of the fossae near the 

 orifices of the posterior nares. 



The vestibule is lined with a scaly epithelium; more posteriorly the nasal 

 cavity is divided into an upper olfactory and a lower or respiratory region. The 



