http://upload.wikimedia.org/wikipedia/commons/d/d2/1543%2CVesalius%27OlfactoryBulbs.jpg, http://upload.wikimedia.org/wikipedia/commons/f/f9/1543,Vesalius%27OlfactoryBulbs.jpg

the olfactory bulbs develop as bilateral evaginations from a region of the prosencephalic neural plate intercalated between the septal and the cortical anlagen (Cobos et al. 2001b, Rubenstein et al. 1998). Comparing the structure of the olfactory bulb among vertebrate species, such as the leopard frog and the lab mouse, reveals that they all share the same fundamental layout(WP).

Part of the telencephalon comprised of anterior outgrowths of either of the cerebral hemispheres in which the olfactory nerve exits.[AAO], Segment of neural tree organ which is continuous with a set of olfactory nerves and an olfactory tract[FMA:77624]., The part of the forebrain in which the olfactory nerves end and the olfactory tracts originate. [Dorian_AF, Elsevier's_encyclopaedic_dictionary_of_medicine, Part_B:_Anatomy_(1988)_Amsterdam_etc.:_Elsevier][VHOG], Part of the rostral part of the cerebrum where axons of olfactory cells from the nasal mucosa terminate. Projects onto olfactory parts of pallium via olfactory tracts

uberon

bulbus olfactorius (Morgagni), olfactory lobe (Barr & Kiernan), olfactory lobe, bulbus olfactorius

The presence of paired evaginated hemispheres and olfactory bulbs in both agnathan and gnathostome radiations suggests that such hemispheres were also present in the common ancestor.[well established][VHOG]

UBERON:0002264

Note that in uberon 'main olfactory bulb' is a separate class, but some ontologies may treat this as partially synonymous. The distinction may only make sense in tetrapods with a vomeronasal organ (olfactory nerves terminate in OB in fishes and in main OB in tetrapods - Butler and Hodos), In most vertebrates, the olfactory bulb is the most rostral (forward) part of the brain. In humans, however, the olfactory bulb is on the inferior (bottom) side of the brain. The olfactory bulb is supported and protected by the cribriform plate which in mammals, separates it from the olfactory epithelium, and which is perforated by olfactory nerve axons. The bulb is divided into two distinct structures, the main olfactory bulb, and the accessory olfactory bulb

• olfactory bulb layer

• anterior commissure anterior part

• olfactory bulb layer