Рет қаралды 818
Olfactory Pathway
- Olfaction statrts as chemical reaction between the odorant and olfactory receptors in the olfactory mucosa at the roof of nasal cavity.
- This chemical reaction turns to action potential in olfactory nerve.
- Olfactory nerve passes through the cribriform of ethmoid and joins the cells in olfactory bulb.
- Second neuron starts from the cells of olfactory bulb and travel through the olfactory tract.
- Fibers in olfactory tract split to 3 stria:
1. Lateral stria that end in primary lfactory area for smell perception (Uncus)
2. Anterior stria that crosses to oppsite side at anterior commissure to ends into the contralateral uncus
3. Medial stria that connect to limbic system, amygdaloid nucleus and anterior perforated substance
- Te connection of oflactory pathway to limib system explains the emotional reaction to smell
- Connection of olfactory pathway to hippocampus for the memory of smell.
- connection with insula, explains the interaction with taste to generate the flavour to food
- Inury of olfactory pathway at any level before the olfactory trigon where the tract divides into stria causes ipsilateral anosmia or loss of smell.
- Injury of olfactory pathway at the area of trigon and behind (uncus, anterior commissure) causes bilateral decrease in smell.