Bronchi: The trachea is divided into 2 main bronchi. They are a pair of tubes that have cartilage plates to keep them open. The bronchi extend into the lungs spreading in a tree-like manner as bronchial tubes. The bronchial tubes subdivide and with each subdivision, their walls get thinner. This dividing of the bronchi into thin-walled tubed results in the formation of bronchioles
Bronchioles: Tiny tubes that extend from the bronchi, they lack cartilage and cilia. Bronchioles passess smooth muscle. They terminate in small air chambers, each of which contains cavities known as alveoli. Alveoli have thin walls, which form the respiratory surface
Lungs: They are two cone shaped organs suspended in the pleural cavities and surrounded by a pleural membrane. Lungs are made of elastic tissue and divide into lobes. The right lung is larger than the left one. Lungs form the most vital component of the human respiratory system. They are located on the two sides of the heart
Lobes: Each lung is divided into lobes, the right one has 3 while the left one had only 2.
References:
Oak, M.. N.p.. Web. !6 Jan 2014
<http://www.buzzle.com/articles/structure-of-the-human-respiratory.system.html>
"Structure of the Respiratory System." Oxford United UK. Web. 16 Jan 2014. <http://www.oxfordunited-yc.co.uk/assets/Academy-images/Resources/Structure-of-the-Respiratory-system.ppt>