What is the blood supply to the olfactory system?

The blood supply to the olfactory system is complex, due to the large number of structures that comprise this system.

The olfactory epithelium, located in the roof of the nasal cavity and upper third of the nasal septum, receives its blood supply mainly from the anterior ethmoidal artery, a branch of the ophthalmic artery.

The olfactory bulb and tract are supplied by orbital branches of the anterior cerebral artery. The latter arteries supply the entire orbital and medial surfaces of the frontal lobe. The olfactory trigone (anterior perforated substance) and proximal segments of the lateral and medial olfactory striae receive their blood supply from small branches that come directly off the anterior Circle of Willis or proximal portions of the anterior and middle cerebral arteries.

The primary olfactory area (comprised mainly of the rostral entorhinal cortex, periamygdaloid cortex, and corticomedial nucleus of the amygdaloid complex) is located in the anteromedial region of the temporal lobe. This area of the brain is supplied mainly by the posterior temporal artery, a branch of the posterior cerebral artery. In addition, the anterior choroidal artery, which supplies the choroid plexus and hippocampal formation, may also contribute some small branches to the amygdala.