THE NASAL MEATUSES 



1205 



conchae (fig. 966). These have a bony framework (described on pp. 83, 110) 

 and are covered by the mucous membrane of the nose. The conchse are not 

 parallel to one another but converge in a backward direction. The superior nasal 

 concha [concha nasalis superior] is the smallest, projects only slightly medialward 

 and downward from the upper, posterior part of the lateral wall, overhanging the 

 groove called superior meatus of the nose. The middle nasal concha [concha 

 nasalis media] is extensive, reaching from the fore part to the posterior confines of 

 the lateral wall. Its free margin is nearly vertical in its anterior one-fourth, hori- 

 zontal and laterally rolled in the rest of its extent. Under coverof this concha 

 runs the middle meatus. The inferior nasal concha [concha nasalis inferior] is the 

 longest, has a lateral attached and an inferior laterally rolled free margin running 

 near the floor of the nasal cavity. Beneath it lies the inferior meatus. 



Meatuses of the nose [meatus nasi] (figs. 966, 968). The name common 

 meatus of the nose [meatus nasi communis] is given to that part of the nasal cav- 



FiG. 967. — Frontal Section through the Facial Portion of the Head of a White 



Man, Age 28 Years. 



Frontal sinus 



Infundibulum 

 Ethmoidal cell 



Middle meatus 



Maxillary sinus 



Inferior meatus 



Middle nasal 

 concha 



Naso-lacrimal 

 duct 



Nasal septum 



Inferior 

 nasal concha 



co-J 



ity which lies between the septum nasi and the nasal conchae and stretches from 

 floor to roof. The three meatuses under cover of the nasal conchse have been 

 mentioned. These passages all communicate freely with the common meatus, 

 extend antero- posteriorly and have a greater capacity in front than behind. 

 The superior meatus [meatus nasi superior] is the smallest of the three. Into 

 it open the posterior ethmoidal cells by one or two small foramina. The spheno- 

 palatine foramen, which communicates with the meatus in the dry skull, is entirely 

 covered up by mucous membrane. The middle meatus [meatus nasi medius] 

 is a much larger passage. Upon its lateral wall is a rounded eminence, the 

 ethmoidal bulla, caused by the middle ethmoidal cells and perforated by the open- 

 ing into them. Inferior to this is a deep curved groove, the hiatus semilunaris, 

 which is continued superiorly by the ethmoidal infundibulum [infundibulum eth- 

 moidale] into the frontal sinus. It also receives the openings of the anterior eth- 

 moidal cells and the maxillary sinus. The inferior meatus [meatus nasi inferior] 

 is the longest of the three. Upon its lateral wall, just inferior to the attachment 

 of the inferior concha, is the slit-like opening of the naso-lacrimal duct [ductus 

 naso-lacrimalis], around the opening of which the mucous membrane forms a valve, 

 the plica lacrimalis (Hasneri). 



Recent investigation of the nasal conchse indicates that two upper conchaj (concha nasalis 

 superior and concha nasalis suprema [Santorini]) are more often present than one. Three upper 

 conchae are not rare. 



