i4o8 HUMAN ANATOMY. 



As upon other parts of the face, plastic operations are very successful owing to 

 the free blood supply. Acne rosacea is common on account of the ready response 

 in vascularity of the nose to external irritating- influences, and to internal disturbances 

 of the circulation, as from heart and lung disease, chronic gastritis, and alcoholism. 

 Furuncles and superficial infections are frequent because of the number of sebaceous 

 and sweat glands present. Lupus and — in the alar sulcus — rodent ulcers are com- 

 mon because of the constant exposure of the nose to external irritation and to 

 lowering of temperature, depressing its vital resistance. Frost-bite of the nose is 

 also common, especially about the tip, because of its exposed position and the lack 

 of protection to the delicate vessels from overlying tissues. 



The nerve supply to the nose is likewise very free, as is shown in a practical 

 manner by the pain which accompanies inflammatory conditions, especially those 

 involving the lower cartilaginous portion where the skin and subcutaneous tissues 

 are very adherent. The resulting exudate is therefore much confined, pressing 

 upon the nerves ; this accounts also for the frequency with which gangrene occurs 

 under these circumstances. 



Watering of the eyes from irritation of the skin or mucous membrane of the 

 nose is due to the free nerve supply, and to the fact that the same nerve, the tri- 

 geminal, supplies the nose and the lachrymal apparatus ; as a portion of the nasal 

 chamber is supplied by a branch of the ophthalmic nerve, raising the eyes to the sun 

 will often give the added irritation necessary to precipitate a sneeze when the nasal 

 stimulus suggests one, but is not quite strong enough unaided. Cough and bronchial 

 asthma have resulted from nasal affections due to the indirect relations between 

 the fifth cranial nerve and the pneumogastric. As the olfactory portion of the 

 nasal fossa is in the upper portion of the cavity, an earnest effort to recognize 

 an odor or to enjoy one to the utmost, is accompanied by a deep inspiration 

 through the nose with dilatation of the nostril. In paralysis of the facial nerve, 

 the involvement of the dilatores naris has been thought to explain -the lessening of 

 the olfactory sense sometimes seen in this condition. Paralysis of the levatores 

 alae nasi muscles has permitted the nostrils to close during inspiration, causing stridor 

 and mouth-breathing. The loss of the sense of smell is a not uncommon result 

 of severe blows, especially on the forehead, and may be due to (a) concussion of 

 the olfactory bulbs ; (d) fracture of the cribriform plate of the ethmoid ; (c) injury 

 to the olfactory roots where they cross the lesser wing of the sphenoid ; or (d) 

 fesion of the olfactory nerx^es where they traverse the cribriform foramina. Sneezing 

 from irritation of the nose is probably due to the indirect relationship between the 

 fifth pair and the vagus and may be so violent that serious injury may result, as in 

 cases in which a subcoracoid lu.xation of the shoulder, a fracture of the ninth rib, 

 and the rupture of all the coverings of a large femoral hernia were produced by 

 this act (Treves). 



The abundant sweat and sebaceous glands in the skin of the nose account for 

 the frequency with which acne vulgaris attacks it. The alae, the only movable por- 

 tions, take part in the movements of expression, as in contempt and scorn. 



Fractures of the nose are common because of its exposed position, and of the 

 frequency of blows and other forms of violence applied to the face. Their chief 

 importance depends upon the prominence of the nose as a feature of the face, any 

 change in its shape attracting general attention. The fracture occurs most com- 

 monly in the lower part, because of the greater weakness of the bones and their greater 

 prominence at that level. In its upper part, the relative depression of the dorsun"!, 

 the greater thickness of the bones, and their more firm support, make fracture less 

 common. On the other hand, the higher fractures are more dangerous because of 

 their possible relation with the cribriform plate and sinuses of the ethmoid bone, the 

 frontal sinuses and the nasal duct. Involvement of the cribriform plate is in effect a 

 compound fracture of the base of the skull, exposing the meninges to the danger of 

 infection. Fractures of the nose are almost always compound, because of the 

 intimate adhesion of the mucous membrane to the bone, with little intervening 

 tissue, so that when the bone breaks the overlying adherent tissue is torn through. 

 This accounts for the practically uniform occurrence of epistaxis, on account of which 

 it is often difficult to detect the presence of escaping cerebro-spinal fluid when the 



