The interactive dog atlas · Organs · Head

Olfactory bulb bulbus olfactorius

The olfactory bulb is the first station of scent in the brain: a small bulb at the front end of the brain, right above the back of the nasal cavity.

Educational material, not a diagnostic tool. Written by the Mantrailing România team from veterinary sources we read. Updated 14.11.2026.

Dog in left lateral view — exterior, muscles, skeleton and organs Vector study after the Ellenberger, Baum and Dittrich plates: a standing dog, head to the left, deep chest and digitigrade limbs. The four layers use the same contour: exterior with body regions, superficial muscles, skeleton and organs.
  1. Olfactory bulb
  2. Brain
Olfactory bulb on the atlas drawing, "Organs" layer, with the neighbouring structures. Left lateral view, after the Ellenberger, Baum and Dittrich plates.

Where it is

At the front end of the brain, below the frontal lobes, on the cribriform plate.

Layer
Organs
System
Nervous system
Region
Head

What it is and what it does

The olfactory bulb is the ventral structure of the hemisphere, part of the rhinencephalon, resting on the cribriform plate of the ethmoid, through which the olfactory nerves enter; the olfactory peduncle attaches it to the brain. Here the axons of the neurons from the nose synapse in glomeruli with the mitral cells, whose axons leave through the olfactory tract. In the dog it takes up about 0.31 % of brain volume, measured on five fixed brains (Kavoi and Hassanali 2011).

Worth remembering

Its share of the brain has been measured (0.31 % in the dog); “X times bigger than in humans” is not a measurement.

Names

  • Latin term: bulbus olfactorius.
  • In Romanian: Bulbul olfactiv (Romanian page).

In the atlas lessons

Journey of a scent (5 min):

From the bulb, the signal goes to the piriform lobe, then to the amygdala, the hippocampus and the frontal cortex: steps 13–19 of the “Journey” and the “Dog brain” page.

The head: what you see, what is underneath (6 min).

The brain and scent: where the trail ends up (7 min):

The olfactory bulb sits on the cribriform plate, under the frontal lobes: the first station of a scent. In the dog, 0.31 % of brain volume, measured on five brains (Kavoi 2011).

Guides it appears in