Thursday, June 11, 2009

Olfactory Bulb

The olfactory bulb is the part of the vertebrate forebrain that is involved in olfaction, that is to say the perception of odors. In humans, the olfactory bulb is on the inferior and bottom side of the brain. The olfactory bulb is supported and protected by the cribriform plate, which separates it from the olfactory epithelium, and which is perforated by olfactory neurons axons.

The olfactory bulb is divided into two different structures: the main olfactory bulb, and the accessory olfactory bulb. The main olfactory bulb has a multi-layered cellular architecture made up of the glomerular layer, external plexiform layer, mitral cell layer,internal plexiform layer, granule cell layer. the glomerular layer receives direct input from olfactory nerves, which consist of axons from approximately ten million olfactory receptor neurons in the olfactory mucosa, a region of the nasal cavity.