The lungs, airways and muscle of respiration are somehow the major parts of the respiratory system. Within this, let's always remember that respiratory means breathing, therefore, the said system involves mainly in breathing. The tricky part is, the said breathing involves inhaling and exhaling gases where carbon dioxide and oxygen takes place; inhaling for oxygen and exhaling for carbon dioxide. The lungs, is one of the major parts of respiratory system. This is where the gas exchange occurs. The airways are the aisle of the air that starts within the mouth or nose and down into the bronchioles; and the muscle of respiration where it s responsible for inhaling and exhaling. They are muscles somehow.This 3 major parts mainly build up the respiratory system of biotic factors.
Hope it Helps =)