Corpus: Olfactory pathway

The term olfactory tract refers to special viscerosensitive fibres from the mucous membrane of the nose to primary and secondary olfactory cortex areas of the cerebrum.

First neuron[Bearbeiten]

The first neuron is formed by the specialised sensory cells of the nasal mucosa (primary sensory cells), the olfactory cells. Their processes (fila olfactoria) pass through the lamina cribrosa ossis ethmoidalis, above which they unite to form the first cranial nerve (nervus olfactorius) and terminate in the mitral cells of the olfactory bulb.

Second neuron[Bearbeiten]

The second neuron is located in the olfactory bulb. Initial processing of the incoming stimuli by mitral cells and tuft cells already takes place here. The information travels from the olfactory bulb via the olfactory tract to the olfactory cortex with the piriformis area and the medial part of the corpus amygdaloideum.

Primary olfactory cortex[Bearbeiten]

In the trigonum olfactorium, the tractus divides into the stria olfactoria lateralis and the stria olfactoria medialis, which lead to the primary olfactory cortex, where olfactory perception enters consciousness.

Stria olfactoria lateralis[Bearbeiten]

It projects to:

• Area piriformis
• Area entorhinalis
• Amygdala

Stria olfactoria medialis[Bearbeiten]

Its projection targets include:

• Tuberculum olfactorium
• Septal area

From the area septalis, the information travels via the stria medullaris to the nuclei habenulares in the habenulae, which transmit the information to the brain stem, where autonomic cranial nerve nuclei are activated.

Secondary olfactory cortex[Bearbeiten]

The orbitofrontal cortex represents the secondary olfactory cortex. Here the information overlaps with secondary cortical areas for taste information, which is probably the reason why the senses of smell and taste are so closely linked.

see also: taste pathway