1. Olfactory and gustatory system
Dr. Katalin Gallatz

2. OLFACTION
Olfctory region of the nasal cavity contain olfactory epithelium with olfactory receptors, supporting cells, basal cells
Olfactory receptors are primary sensory epithelial cells (modified neurons)
Surfaces are coated with mucous secretions from olfactory glands
Olfactory reception involved detecting dissolved chemicals (odorant materials) as they interact with odorant binding proteins

3. OLFACTION Olfactory discrimination
Can distinguish thousands of chemical stimuli
CNS interprets smells by pattern of receptor activity
Olfactory receptor population shows considerable turnover
Number of receptors declines with age

4. Olfactory epithelium: primery sensory epithelial cells
Parts of the olfactory system
Olfactory epithelium:
primery sensory epithelial cells
central branches - fila olfactoria
Olfactory bulb:
mitral and tufted cells
axons olfactory tract
Olfactory tract:
stria olfactoria medialis, intermedius
et lateralis
Olfactory areas:
praepiriform cortex
entorhinal cortex, AMYGDALA

5. o t o

6. OLFACTORY REGION
Aromas reach the olfactory epithelium

7. ORTHONASAL and
RETRONASAL OLFACTION

8. OLFACTORY EPITHELIUM
Specialized ,,neurons” present in the olfactory epithelium in the nose.
They project cilia into a mucus layer. The odorant receptors of the cilia are able to bind to odorant molecules.
Each olfactory receptor is
specialized for 1 odorant molecule
ORC = olfactory receptor cells

9. Olfactory transduction - G-Protein Receptor

10. Olfactory cells: - primary sensory epithelium
- bipolar cells: dendritic process to the direction of the surface,
olfactory processes to the direction of the lamina propria
fila olfactoria
olfactory bulb

11. Olfactory bulb Olfactory fila synapse with the dendrites
of the mitral and tufted cells
olfactory glomerulus
2. Axons of the mitral and tufted cells
form the
olfactory tract
3. Inhibitory granule cells get centrifugal fibers from the anterior
olfactory nucleus locus coeruleus and dorsal raphe nucleus, and inhibit the
mitral and tufted cells

12. OLFACTORY BULB
LAMINA CRIBROSA
OLFACTORy
EPITHELIUM

13. Olfactory tract: axons of the mitral and tufted cells terminate in the
anterior olfactory nucleus and in the
olfactory cortical areas
Fibers from the anterior olfactory nucleus synapse with the granule cells of the
contalateral olfactory bulb

14. Olfactory cortical areas:
amygdala,
Prepiriform cortex – uncus
Entorhinal cortex – parahyppocampal gyrus
Orbitofrontal cortex

15. OLFACTORY PATHWAYS

16. OLFACTORY PATWAYS
ORBITOFRONTAL CORTEX

17. Secunder olfactory cortex
OLFACTORY PATHWAYS
Secunder olfactory cortex

18. Gustatory system

19. Taste bud secondary sensory epithelial cells supporting cells
basal cells

21. Gustatory discrimination
Primary taste sensations
Sweet, sour, salty, bitter
Receptors also exist for umami and water
Taste sensitivity shows significant individual differences
The number of taste buds declines with age

22. Umami, or savory taste, is one of the five basic tastes (together with sweetness,
sourness, bitterness, and saltiness).
It has been described as brothy or meaty.
People taste umami through taste receptors that typically respond to glutamate.
Glutamate is widely present in meat broths and fermented products, and commonly
added to some foods in the form of monosodium glutamate (MSG). [
Since umami has its own receptors unami now is considered to be a distinct taste.

23. TASTE RECEPTORS

24. GUSTATORY PATHWAY TASTE BUDS VII., IX., X. I. neuron
Geniculate ggl VII.
inf. ggl IX. n
inf. X. n.
VII. X.
IX.
II. neuron
nucl.of solitary tract
III. neuron
VPM parvocellular part
Postcentral gyrus - insular cortex

25. Gustatory system 1.Taste buds 2.VII., IX., X. 3.geniculate ggl. VII.n.
inf. ggl. of n. IX.
inf. ggl of n.X.
4. nucl. of solitary tract
5. VPM parvocellular part
6. postcentral gyrus

27. Connection between the olfactory and gustatory system
nucleus of solitary tract
parabrachial nucleus
hypothalamus
amygdala

28. Thank you for your attention!