3 



HEAD AND NECK 



branch of the ophthalmic division of the trigeminal nerve. The 

 nerve will be found emerging between the lower border of the 

 nasal bone and the lateral cartilage of the nose. After its 

 emergence it descends to the tip of the nose, supplying filaments 

 to the skin. After it has been displayed, strip off the nasalis 

 muscle and the remains of the integument and examine the 

 cartilaginous part of the nose. 



Cartilagines Nasi. In addition to the septal cartilage, 

 which will be more appropriately studied in the dissection of 

 the nasal cavities, two cartilaginous plates will be found 

 upon each side. They are : 



1. The lateral cartilage. 



2. The cartilage of the ala. 



External nasal nerve 



Tl 



jar Lateral cartilage 



Minor alar cartilages 

 Major alar cartilage 



FIG. 10. Cartilages of the Nose. 



The lateral cartilage is triangular in form. Its posterior 

 margin is attached to the lower border of the nasal bone and 

 the upper part of the sharp margin of the nasal notch of 

 the maxilla. The upper part of the medial border is con- 

 tinuous with the corresponding cartilage of the opposite side, 

 and also with the subjacent anterior border of the septal 

 cartilage of the nose; but the lower parts of the medial 

 borders of the lateral cartilages are separated by a small 

 interval in which the margin of the nasal septal cartilage is 

 seen. The inferior border of the lateral cartilage is connected 

 with the lateral part of the alar cartilage by fibrous tissue. 



The alar cartilage is a bent plate which is folded round 

 the anterior part of the nasal orifice. The lateral part is 

 oval, and reaches neither down to the margin of the nostril, 



