Bones of the Skull. 



61 



Probe in canal is nasolacrimalis 



Os nasale 



Sinus frontalis 



Probe from sinus frontalis in the infundibulum ethmoidale 

 Processus uncinatus 



/ Hiatus semilunaris 

 / Bulla ethmoidalis 



/ /' Probe from sinus frontalis in the infundibulum ethmoidale 

 Site of the actual opening of the sinus maxillaris 



Opening of the posterior ethmoidal cells 



Probe in the apertura sinus sphenoidalis 



Sinus sphenoidalis 



'v, / 

 i^N 



Os lacrimale 



Foramen sphenopalatinum 



Lamina medialis processus pterygoidei 



Pars perpendicularis ossis palatini 

 Probe in canalis nasolacrimalis 



74. Nasal Cavity, CClVUm nasi, right lateral wall, from the left. 



(The middle and inferior turbinated bones have been partially removed.) 



In the meatus nasi inferior, near the anterior end, lies the lower opening of the 

 canalis nasolacrimalis. This goes out from the fossa sacci lacrimalis and is, formed lateral- 

 ward and in front by the sulcus lacrimalis of the corpus and of the proc. frontalis maxillae, 

 medianward and behind by th sulcus lacrimalis oss. lacrimalis and the proc. lacrimalis conchae 

 nasalis inferioris; it is directed from above downward and at the same time somewhat from 

 before backward. 



Into the mealns nasi medius opens the sinus maxillaris. The opening 1 does not corre- 

 spond to the whole hiatus maxillaris of the upper jaw bone, for this is essentially narrowed 

 by the overlapping of the neighboring bones, namely, by the pars perpendicularis oss. palatini 

 from behind, the proc. maxillaris conchae nasalis inferioris from below, the proc. ethmoidalis 

 conchae nasalis inferioris and the proc. uncinatus oss. ethmoidalis in the middle. The actual 

 opening lies lateralward from the proc. uncinatus at the bottom of a narrow oblong fossa 

 (infundibulum ethmoidale), which extends along the proc. uncinatus upward and forward, 

 widens like a funnel and opens above into the sinus frontalis, but in addition receives the 

 openings from the anterior ethmoidal cells; besides this connection between the frontal and 

 nasal cavities there is also a second just medianward from the processus^ uncinatus. Projecting 

 downward into the infundibulum ethmoidale from the outside there is usually a vesicular eth- 

 moidal cell, the bulla ethmoidalis; the narrow sickle-shaped slit between this and the upper 

 margin of the proc. uncinatus, the entrance to the infundibulum, is called the hiatus semilunaris. 



Into the meatus nasi superior open the middle and posterior ethmoidal cells. 



Above, the concha superior is situated the recessus sphenoethmoidalis (see Fig. 23); 

 the sinus sphenoidalis opens above this from behind by means of the apertura sinvs sphenoidalis. 



