ANATOMY OF REGIONS. 
201 
smaller, and equally anastomosing vessels, coming from the borders of 
the organs. At the anterior part, below the portion of the mucous mem¬ 
brane which is covered with glands, the veins, by their disposition, re¬ 
minds one of the admirable venous network of the palate. 
This disposition is more marked yet upon the turbinated bones, and 
especially over the cartilaginous section. Veins are more numerous 
upon the roof, and the posterior part of the floor, than in all the other 
points of the meatus. Those of the inferior turbinated bone are paral¬ 
lel to its direction ; in the superior, parallel to its extremity and middle 
part, but converge together and unite to the nasal vein in front of the small 
ethmoidal volutes. In all the points where the mucous membrane is thick 
and loose, the veins occupy the underneath connective tissue, or rather 
form a second layer under the dermis; this disposition is well marked 
on the level of the cartilages. Everywhere, on the contrary, where this 
membrane is thin, and adherent to tissues underneath, the venous canal is 
made at the expense of the dermis alone, if resting upon cartilage, and part¬ 
ly in the dermis and bone if this tissue is covered by the mucous membrane. 
This disposition is well shown in a dry specimen, where the papyraceous 
sheath of the turbinated bones is covered with furrows, indicating the 
course followed by the veins. From the examination of this rich vas¬ 
cular network, the gravity of some epistaxis can be appreciated. 
The lymphatics form upon the olfactory mucous membrane a beautiful 
superficial network, whose trunks run to the submaxillary ganglions, and 
during inflammation of the pituitary membrane, the ganglions are seen 
swelling to such a size as to sometimes fill the submaxillary space 
entirely, or even extend beyond the branches of the maxillary 
bone. 
This is specially marked in diseases of the lymphatic system. We 
all know that one of the pathognomonic symptoms of glanders is the 
tumefaction of the sub-lingual ganglions when the pituitary is itself in¬ 
flamed or ulcerated. This becomes, therefore, a means of the appre¬ 
ciation of deep glanderous chancres, that may escape detection by 
examination of the nostrils. 
The nerves come from the first and fifth pair—the first seem to be 
essentially for olfaction, as their name indicate, and though cases of con¬ 
genital absence of olfactory nerves not suspected during life, had been 
observed. M. Claude Bernard reports an observation which proves that 
olfactory nerves can be missing though the sens of olfaction be present. 
They are undoubtedly replaced by nerves of the third pair, which act 
also as nerves of the organs of smell. 
