

THE ETHMOID BONE 



155 



by articulation with the sphenoidal concha and orbital process of the palatine. 

 The lateral surface (Fig. 152) is formed of a thin, smooth, oblong plate, the lamina 

 papyracea (05 planum), which covers in the middle and posterior ethmoidal cells 



A la 



Ethmoidal 

 cells 



Perpendicular 

 plate 



Uncinate process 



FIG. 152. Ethmoid bone from the right side. 



and forms a large part of the medial wall of the orbit; it articulates above with 

 the orbital plate of the frontal bone, below with the maxilla and orbital process 

 of the palatine, in front with the lacrimal, and behind with the sphenoid. 



In front of the lamina papyracea are some broken air cells which are overlapped 

 and completed by the lacrimal bone and the frontal process of the maxilla. A 



Frontal sinus 



Crista galli 



Sella turcica 



Openings into 

 maxillary sinus 

 Medial pterygoid plate 

 Hamulus 



curv 



FIG. 153. Lateral wall of nasal cavity, showing ethmoid bone in position. 



ed lamina, the uncinate process, projects downward and backward from this 

 part of the labyrinth; it forms a small part of the medial wall of the maxillary 

 sinus, and articulates with the ethmoidal process of the inferior nasal concha. 





