Anatomy of the Lungs

The lungs are made up of a series of dividing airways called bronchi that lead to clusters of alveoli. The lungs can be imagined as an upside down tree where the branches are the bronchi and alveoli are like clusters of grapes at the ends of the branches. In the alveoli oxygen and carbon dioxide are exchanged to and from red blood cells in the blood steam. The trachea, which is the largest airway, connects the lungs to the outside world.

The lungs are separated into 5 segments called lobes (3 on the right and 2 on the left). Each lobe is connected to the trachea by an individual bronchus. Blood is carried from the right side of the heart into the lungs by the pulmonary artery. Oxygenated blood returns to the left side of the heart via the pulmonary veins.

The alveoli are lined with a material called surfactant that prevents them from collapsing. Microscopic collagen fibers provide the support for the lung while elastin fibers give the lung elastic recoil. The collagen and elastin are part of the internal structure that surrounds and supports the alveoli, while allowing your lungs to inflate and deflate while you breathe.