nasal chamber -external nares are 2 in number ie

Question

NASAL CHAMBER -

1. External nares are 2 in number, i.e., dirhynous. Situated at lower side of nose. Open into nasal chamber.
2. Nasal chamber opens into pharynx by internal nares.
3. Nasal chamber is devided into two fossae by Nasal septum or Mesethmoid septa.
4. In each fossae 3 regions are clear - vastibular region, respiratory region and olfactory region.
5. The floor of nasal chamber is formed by palate.
6. Vestibular region is ectodermal in origin, covered by hairy skin. Hair check the dust particles.
7. Respiratory region is covered by pseudo stratified sensory vascularized cilliated epithelium.
8. This region acts as a air conditioning and filtering unit.
9. Olfactory region is covered by olfactory epithelium.
10. Arising from the wall of each nasal chamber 3 bonny ridges nasal conchae are sup. middle & inferior.
11. Conchae are covered with mucous membrane, these conchae increase surface area.

Functions -

1.      To detect smell

2.      To check dust particle

3.      To keep air moist

4.      To destroy bacteria by mucous.

5.      Functions as air conditioning.