1. The nose
knows

2. The nose: Sense of Smell
Besides filtering, warming and humidifying air the nose’s other job is as an olfactory (smell) organ.
The perception of odours is called olfaction
The top of the nose is formed by 2 bones – nasal bones
The tip of the nose is made of cartilage *
Epithelium produces mucus
in nasal cavities

3. The olfactory membrane (smell) is located in the top of the nasal cavity
this area has over 12 million specialized nerve cells that detect odours called the olfactory bulb.
The nose can detect about ,000 different odours
The information is sent directly to the olfactory area of the brain *

5. To smell something… Must be gaseous(volatile), transported by air
Must be odoriferous, of a chemical nature that stimulates smell receptor cells.
Must occur in sufficiently high concentrations to stimulate smell receptor cells.
Must reach the receptor cells in the olfactory membrane (not blocked by mucus)

6. How we smell
Odour molecules dissolve in the mucus in the nasal cavity (1)
They touch the dendrites of the olfactory cells (2) located in the olfactory epithelium
A nerve signal begins
The olfactory cells pass the information to the olfactory nerve (3)
Information is sent to the temporal lobe (4)
FUN FACT:
The sense of smell tends to deteriorate with age.

7. How we smell