Identify the parts labelled 1-8 in the diagram given below.
1. Nasal cavity, 2. Pharynx, 3. Trachea, 4. Lungs, 5. Bronchi, 6. Bronchioles, 7. Alveoli, 8. Diaphragm
There are 3 major parts in the respiratory system - the airway, the lungs, and the muscles of respiration. The airway includes the nose, mouth, pharynx and trachea. At the end of the trachea, the airway splits into left and right branches, which are known as the primary bronchi. The left and right bronchi run into each lung and branch off into smaller secondary bronchi and further into many smaller tertiary bronchi. They continue branching and finally, tiny terminal bronchioles conduct air to the alveoli of the lungs. The diaphragm and the related intercostal muscles are the muscles of respiration that contribute by expanding and contracting the thoracic cavity and consequently, the lungs.