39 



HEAD AND NECK 



which corresponds to the vestibule of the nose, and forms 

 the medial wall of this subdivision of the nasal cavity. 

 The vestibular part of the partition is clothed with skin, 

 continuous with the external integument ; from this a 

 number of stiff hairs, termed vibrissce, project. Over the 

 rest of its extent the septum nasi is covered with mucous 

 membrane, which is closely adherent to the subjacent peri- 

 osteum forming with it a muco- periosteum ; and it is 



Frontal sinus 



Nasal bone 



Vestibule o 

 nasal cavity 



Opening of 

 vomero-nasal organ 



Sublingual gland- 

 Mandible- 



Septal cartilage 



Perpendicular lamina of ethmoid 

 Vomer 



Sphenoidal air sinus 



Levator cushion 



Opening of auditory 

 tube 



Lateral pharyngeal 

 recess 

 Pharyngeal tonsil 



Atlas 



/.;;// Soft P alate 



ts ''/j Transverse ligament 



Epistropheus 

 ' Epiglottis 



Hyoid bone 



FIG. 153. Antero-posterior section through the Nose, Mouth, and 

 Pharynx, a little to the left of the median plane. 



separable into two districts, viz., a lower or respiratory 

 area, and a much smaller upper or olfactory area, comprising 

 not more than the upper third of the septum, in which 

 branches of the olfactory nerve spread out. The respiratory 

 mucous membrane is very thick and spongy. It is highly 

 vascular and contains numerous mucous glands. The minute 

 orifices of the gland ducts can be detected by the naked 

 eye. Over the olfactory district of the septum the mucous 

 membrane is softer and more delicate, and not so thick. In 

 the fresh state it presents a yellowish colour, and the glands 

 are smaller. 



