The sphenopalatine artery and its branches form the arterial plexus situated in the septum nasi and the ventral nasal concha. However, both of the sphenopalatine and the external ethmoidal arteries share in the formation of the arterial plexus of the dorsal nasal concha. The corresponding venous plexuses are formed by the tributaries of the sphenopalatine vein only.
The right and left venous nasal septal plexuses join each other just caudal to the free border of the nasal septum, however, there is no connection between the other plexuses. The abundent quantity of vascular plexuses present within the nasal cavity of the mule, is possibly to accomodate the inspired air to the body temperture especially in hot atmosphere and chilling tempests.