Understanding the Lungs: Structure and Function

The lungs are an essential part of the respiration process, transferring air breathed and exhaled in and out of the bloodstream. They consist of several parts which progressively get smaller, enabling air to be transferred.

Trachea

• The trachea (windpipe) brings the air in and out of the lungs and is connected to the bronchi.

Bronchi

• The bronchi are two large air passageways connected to the trachea. They carry the air to the two lungs, and pass it on to the bronchiole.

Bronchiole

• Bronchiole are much smaller tubes, leading off the bronchi carrying the oxygen to the alveoli.

Alveoli

• Alveoli are the "working parts of the lungs". They consist of millions of tiny air sacks with walls full of blood vessels. These walls are where gas exchange takes place between the lungs and the bloodstream.