The Lungs
Explore the structure of the lungs, their lobes, and the tissue that surrounds them.
Structure of the lungs
The lungs are a pair of spongy, elastic organs located in the chest cavity. The right lung has three lobes, and the left lung has two, leaving room for the heart.
Two lungs, five lobes
The right lung's three lobes and the left lung's two lobes sit on either side of the heart.
Three lobes
The right lung is divided into the superior, middle, and inferior lobes.
Two lobes
The left lung has superior and inferior lobes, and is slightly smaller to accommodate the heart.
Protective lining
A double-layered membrane called the pleura surrounds each lung and reduces friction during breathing.
Internal branching
Inside each lung, the bronchi continue branching into bronchioles that end in clusters of alveoli.
The lungs are mostly airway and alveoli, not solid tissue.
Most of the lung's volume is taken up by air-filled spaces and the branching airway network that leads to them.
The pleural cavity
The pleural cavity is a thin, fluid-filled space between the two layers of the pleura. This fluid allows the lungs to slide smoothly against the chest wall during breathing.
Why lobes matter
Because the lungs are divided into lobes with their own blood supply and airway branch, damage to one lobe does not necessarily affect the others.
Two lungs, five lobes total.
Remembering three lobes on the right and two on the left helps explain many lung imaging and anatomy references.