62 



Bones of the Skull. 



Sinus frontalis 

 Crista galli 



Lamina perpendicularis ossis ethmoidalis 

 Sinus sphenoidalis 

 / Sella turcica 



Os nasale 



Concha 

 nasalis inferior 



CUvus 



Vomer 

 Processus palatinus maxillae 



75. Nasal cavity, cavum nasi. 



Bony nasal septum, septum nasi osseum, from the left. 



The upper, narrowest wall of the nasal cavity (see also Figs. 73 and 74) is formed 

 by the lamina cribrosa oss. ethmoidalis ; the lower, broader Wall by the slightly concave upper 

 surface of the processus palatini maxillae and the partes horizontales oss. palatini. 



The anterior wall (see also Figs. 57, 7^ and 74) of the nasal cavity proper is bony 

 above only and is there formed by the spina frontalis of the pars nasalis oss. frontalis and 

 the ossa nasalia; below it presents the apertura piriformis (0. T. anterior nares), opening 

 toward the facial surface. This is "pear-shaped", narrow above, broad below and is surrounded 

 above by the free margins of the ossa nasalia, lateralward by the incisurae nasales of the 

 upper jaw bones, below by the ossa incisiva and the spina nasalis anterior. 



The septum nasi osseum (bony nasal septum), which, within, subdivides the nasal 

 cavity, lies in the median plane and is usually somewhat deflected toward one side or the 

 other. This deviation, however, is never met with at the posterior margin. The septum begins 

 in front, behind the apertura piriformis, by a deep notch which is filled up by the cartilago 

 septi nasi, ends free behind at the posterior boundary of the nasal cavity and otherwise extends 

 without essential interruption from the upper to the lower wall. Its upper part is formed by 

 the lamina perpendicularis oss. ethmoidalis, the lower by the vomer. Above it unites in front 

 with the spina frontalis of the pars nasalis oss. frontalis and with the lamina cibrosa oss. 

 ethmoidalis, behind with the crista sphenoidalis and the rostrum sphenoidale ; below it lies on 

 the crista nasalis of the united maxillary and palate bones. 



The nasal cavity is connected on its upper wall by the openings of the lamina cribrosa 

 with the skull cavity and by the foramina ethmoidalia with the orbit; on its lateral wall by 

 the canalis nasolacrimalis with the orbit, by the foramen sphenopalatinum with the fossa 

 pterygopalatina ; on its anterior wall by the foramina nasalia with the anterior facial surface: 

 on its lower wall by the canalis incisivus with the mouth. 



