AND PHYSIOLOGY. 



413 



762 a. Use of the Bones. — Use of the Cartilages, 

 and the Glands in Integuments.— The bones are the 

 two nasal, which give form to the base of the nose, and fur- 

 nish a firm attachment to the muscles. The cartilage is of 

 use to give form to the nose, w T hile its elasticity lessens the 

 effects of injuries. The integument or skin is quite thick 

 upon this organ, and aids the cartilage in giving form to it. 

 It contains in its substance small glands, which secrete an oil j 

 matter to protect the nose from extremes of weather. These 

 glands are liable to retain dust and other impurities in their 

 orifices, forming the black specks on the nose. 



763. Lined with Mucous Membrane— The whole cav- 

 ity of the nostrils is lined with mucous membrane, which is 

 continuous w r ith the lining membrane of the fauce3 or throat, 

 with which the nostrils are in communication. 



as possible for the expan- 



A Vertical Section of the Middle Part of the Nasal Fossae, giving a Posterior View of 

 the Arrangement of the Ethmoidal Cells, etc. 1, Anterior Fossae of the Cranium. 2, The 

 same covered by the Dura Mater. 8, The Dura Mater turned up. 4, The Crista Galli 

 of the Ethmoid Bone. 5, Its Cribriform Plate. 6, Its Nasal Lamella. 7, The Middle 

 Spongy Bones. 8, The Ethmoidal Cells. 9, The Os Planum. 10, Inferior Spongy Bone. 

 11, The Vomer. 12, Superior Maxillary Bone. 13, Its Union with the Ethmoid. 14, 

 Anterior Parietes of the Antrum Highmorianum, covered by its Membrane. 15, Its 

 Fibrous Layer 16, Its Mucous Membrane. 17, Palatine Process of the Superior Maxil- 

 lary Bone. 18, Roof of the Mouth, covered by the Mucous Membrane. 19, Section of 

 this Membrane. A Bristle is seen in the Orifice of the Antrum Highmorianum. 



762 a. State the use of bone and cartilage in the composition of the nose. Of what ser- 

 vice are the little glands in its skin ? 763. What are the nostrils lined with? 764. De- 

 scribe the cavities of the nostrils. 



764. Cavities of the 

 Nostrils . — Nerve of 

 Smelling — The cavities 

 of the nostrils are very 

 irregular, since upon their 

 own outer sides are found 

 the turbinal bones and 

 a similar scroll-like por- 

 tion from the ethmoid 

 bone, for the purpose of 

 giving as large a surface 



Fig. 373. 



