THE LUNGS

The lungs are pear-shaped structure situated in the thoracic cavity. Each lungs is divided into lobes. The right lung has three lobes, while the right lung has two lobes.  Each lung receives the bronchus. The braochus divides into small units called bronchioles. The bronchioles terminate into sac-like structure called Alveolus, via a tubular structure called the alveoli duct. There are millions sets of alveoli in each of the lungs. Each of the alveoli is surrounded by blood capillaries. Exchange of gases- carbon dioxide and oxygen takes place in the surroundings of the alveoli.