Definition & Part of Respiratoy System

     

Histology of Trachea, Bronchial tree & Bronchus

                           

Histology of Respiratory System

 Defination: Respiratory system consists of the lungs and a series passage leading to them.On the basis of their primary functions,the different parts of respiratory system can be classified into two portion-

1.Conducting  portion  and

2.Respiratory  portion

 Conducting Portion:Provide  a series of air passage and serve a protective function by conditioning the incoming air.The conditioning includes-

  a)Heating the air to body temperature

  b)Moistening the air to prevent desiccation of alveoli

  C)Filtering out the noxious gases and particles.

The Conducting Portion: It Consists of-

 1.Nasal Cavity- It  includes:

                                      -- Cutaneous region

                                         -- Respiratory region

                                         -- Olfactory region

                                         -- Vomaronasal region

                                         -- Paranasal sinus

2. Nasopharynx

3. Larynx

4. Pharynx

5. Trachea

6. Bronchi

7. Bronchioles  

 Respiratory Portion: Gasious exchange take place in this portion.It consists of—

                                                                               i.            Respiratory bronchioles

                                                                             ii.            Alveolar duct

                                                                          iii.            Alveolar sac

                                                                          iv.            Alveoli