Lung Anatomy

The lungs are respiratory organs – we use them to breathe. We breathe in order to get oxygen (O₂) and to get rid of carbon dioxide (CO₂).

We breathe in through the nose or mouth. The air then goes through the larynx and the trachea (also called the windpipe) and into the lungs. We breathe by using the diaphragm, a muscular membrane under the lungs. When the diaphragm the diaphragm contracts and pulls downwards, the lungs expand and air enters the lungs (inhalation). When the diaphragm relaxes, air is exhaled from the lungs.

When the air is in the lungs, it comes enters capillary-lined alveoli (singular alveolus). In the hollow alveoli, gas exchange occurs [oxygen (O₂) is absorbed by blood in the capillaries and carbon dioxide (CO₂) is gotten rid of].

People have two lungs – they are located on either side of the heart within the rib cage. The two lungs are not identical; the right lung has three lobes and the left lung has two lobes.

Lung Glossary

alveoli (singular alveolus)

hollow, capillary-lined structures within the lungs that are the site of gas exchange with the blood [the absorption of oxygen (O₂) and the loss of carbon dioxide (CO₂)]. Each human lung contains about 300 million alveoli.

bronchial tree

the system of airways within the lungs, which bring air from the trachea to the lung’s tiny air sacs (alveoli).

cardiac notch

the indentation in the left lung that provides room for the heart.

diaphragm

a muscular membrane under the lungs. When it contracts and pulls downwards, the lungs expand and air enters the lungs (inhalation). When the diaphragm relaxes, air is exhaled from the lungs.

larynx

a muscular structure at the top of the trachea, containing the vocal cords.

left inferior lobe

the bottom lobe of the lung on the left side of the body.

left superior lobe

the top lobe of the lung on the left side of the body.

right inferior lobe

the bottom lobe of the lung on the right side of the body.

right middle lobe

the middle lobe of the lung on the right side of the body.

right superior lobe

the top lobe of the lung on the right side of the body.

trachea (windpipe)

the tube through which air travels from the larynx to the lungs.