What are the passages that direct air into the lungs known as?

The passages that direct air into the lungs are known as the bronchi. These are the main airways that branch off from the trachea and lead into the lungs. Each bronchus carries air to one of the lungs, allowing for the exchange of oxygen and carbon dioxide during the breathing process. The structure of the bronchi includes smooth muscle and cartilage, which helps maintain their shape and allows them to expand and contract as needed during respiration.

In contrast, alveoli are the tiny air sacs in the lungs where gas exchange occurs, and the trachea is the windpipe that connects the throat to the bronchi, serving as the initial passage for air before it splits into the bronchi. The diaphragm is a muscle that plays a crucial role in the mechanics of breathing by contracting and relaxing to allow air to flow in and out of the lungs, but it does not direct air passages directly.