Question: what are the different parts of respiratory system and their functions?
Answer: Nose and Nasal Cavity. The nose and nasal cavity form the main external opening for the respiratory system and are the first section of the body's airway—the respiratory tract through which air moves. ... 
Mouth. ... 
Pharynx. ... 
Larynx. ... 
Trachea. ... 
Bronchi and Bronchioles. ... 
Lungs. ... 
Muscles of Respiration.