| |
|
|
| |
 |
| Nose - Structure |
|
| Nose is the sense organ for the sense of olfaction or smell. The receptor cells for olfaction are chemoreceptors, stimulated by chemicals. The receptor cells along with other cells form the olfactory epithelium. |
| |
|
| Olfactory epithelium |
| |
| It is a modified pseudostratified epithelium occupying a small area of about 5cm2 in the roof of the nasal cavity. It forms the surface layer in the nasal mucosa near the nasal septum. |
| |
 |
| |
| Human nose showing olfactory bulb. Inset: Magnified view of the olfactory epithelium |
| |
| In man, this area is very small and thus the sense of smell in man is not as developed as some other animals. In animals like the dog, cat, rat, rabbit, etc., the olfactory epithelium occupies a large area and these animals are very sensitive to a wide range of smells. Man is also sensitive to thousands of types of smells but animals like dogs can differentiate between the smells of two people. |
| |
| The olfactory epithelium is made up of three types of cells |
| |
 |
| |
| Olfactory receptor cells |
| |
| They are neurosensory cells that are spindle-shaped. On one end they have sensitive hairs and at the other end they have the nerve fibres. Their life span is two months. |
| |
| Basal cells |
| |
| They are the cells that give rise to new olfactory receptor cells. |
| |
| Supporting cells |
| |
| They are columnar epithelial cells occurring between the receptor cells and providing support. |
| |
|
|
| |
|
|
| |
|
|
|
|
|
Customer Care
Click to get customer service, technical support and subscription help.
Refer-A-Friend
Get One Month Free!
When you refer a friend
Nervous Coordination and Integration
|
|
|
