TURBINATED BONES. 61 



extremity forming a pulley, round which the tendon of the tensor 

 palati muscle plays. 



VOMER. 



This, the only single bone in the superior facial region, is a 

 long bone constructed of two thin ^^lates, with a deep groove 

 between, and extends along the middle line of the floor of the 

 nasal chambers from the sphenoid to the premaxilla. It presents 

 two surfaces, two borders, and two extremities. 



The two lateral surfaces, narrow anteriorly and wider poste- 

 riorly, are smooth, and, in the fresh state, covered by mucous 

 membrane. The superior border is deeply grooved for the 

 reception of the cartilaginous septum of the nose ; the inferior 

 border is sharp and smooth in its posterior half, where it forms 

 the division between the posterior nares ; the remaining portion 

 is broad, flat, and slightly dentated to articulate with the maxil- 

 lary bones. The posterior extremity is broad from side to side, 

 convex below, and concave above, where it opens out into a 

 crescentic border which embraces the sphenoid, and forms an 

 irregular hiatus between the two bones for the passage of the 

 nerves and blood-vessels which supply the septum. The ante- 

 rior extremity is flat, and rests on the palatine process of the 

 premaxilla. 



The vomer articulates with the sphenoid, ethmoid, palatine, 

 pterygoid, superior maxillary, and premaxillary bones. 



TURBINATED BONES. 

 (Fig. 13. 6, 12.) 



These, also called the turbinals, four in number, one superior 

 and one inferior on each side, are found in the nasal chambers, 

 and are irregular bony columns, larger posteriorly than anteriorly, 

 flattened from side to side, and hollowed within, dividing the 

 nasal passages into superior, middle, and inferior meati. 



The superior or ethmoidal turbinal is attached to the ridge 

 on the nasal bone and to the ethmoid, and the inferior or 

 maxillary turbinal to the ridge on the superior maxilla. They 

 are formed of very delicate and reticulated rolls or convolutions 

 of bone void of periosteum. The superior is the larger of the 

 two, and extends from the ethmoid to near the external opening 

 of the nose ; a tranverse plate divides it into two portions, of 



