92 SURGICAL APPLIED ANATOMY. [Chap. vi. 



and inferior parts of the septum. These glands 

 may be the subject of considerable hypertrophy. They 

 are capable of providing also a very copious watery 

 secretion, which has, in some cases of chronic coryza 

 following injury, been so free as to be mistaken for an 

 escape of cerebro-spinal fluid. There is also much 

 adenoid, or lymphoid, tissue in the nasal mucous mem- 

 brane, which is the primary seat of the chief scrofulous 

 affections that invade this part. So thick and lax is 

 the normal mucous membrane over the lower borders 

 and posterior extremities of the middle and inferior 

 turbinated bones that it forms in these situations a 

 kind of soft cushion. This condition is mainly due to 

 the presence of a rich submucous venous plexus, the 

 vessels of which run, for the most part, in an antero- 

 posterior direction. Over the lower turbinate bone the 

 veins form a kind of cavernous tissue, " the erectile 

 body." When turgid with blood, it swells so as to 

 obliterate the interval between the bone and the 

 septum. When the seat of chronic inflammation, the 

 mucous membrane over the inferior bone may appear 

 as a polypoid swelling. The great vascularity of the 

 mucous membrane is probably for the purpose of 

 raising the temperature of the inspired air. From the 

 construction of the fossse the inspired air is encouraged 

 to pass a long the middle nieatus, the expired air along 

 the lower nieatus. From the comparatively lax at- 

 tachment of the mucous membrane of the septum to 

 the parts beneath, it happens that hsematomata are 

 often met with beneath the septal mucous membrane 

 after a blow on the nose. 



Polypi are often met with in the nose. They 

 are of two kinds, the mucous or myxomatous polyp 

 that springs usually from the mucous membrane 

 over the middle or inferior turbinate bones, and the 

 fibrous or sarcomatous polyp that usually takes origin 

 from the periosteum of the nasal roof, or from that of the 



