[1]the trachea is the windpipe, which conveys air from the larynx to the two main bronchi, with the lungs and their air sacs as the ultimate destination

[2]Trachea is supported by c-shaped rings of cartilage which hold them in place when there is less air inside it. So, the walls of trachea do not collapse even when there is a little air.

The Function of the Trachea

The trachea, also known as the windpipe, is a tube-like structure made of cartilage rings and smooth muscle fibers that connects the larynx (voice box) to the bronchi of the lungs. Its function is to transport air from the upper respiratory tract to the lungs, allowing for gas exchange to occur.

Why the Tracheal Walls Do Not Collapse

The walls of the trachea are made up of cartilage rings and smooth muscle fibers that provide structural support and prevent collapse, respectively.

Cartilage Rings

The cartilage rings are C-shaped and are arranged in a way that leaves the posterior aspect of the trachea open, allowing for expansion during inhalation. The rings also provide a degree of flexibility, allowing the trachea to bend slightly without collapsing.

Smooth Muscle Fibers

Smooth muscle fibers are located in the walls of the trachea and are responsible for maintaining its diameter. These fibers can contract and relax, allowing for adjustments in the diameter of the trachea as needed. During inhalation, the muscles relax, allowing the trachea to expand and air to flow freely. During exhalation, the muscles contract, narrowing the trachea and helping to force air out of the lungs.

Conclusion

In summary, the trachea serves an important function in the respiratory system by transporting air from the upper respiratory tract to the lungs. Its walls are designed to prevent collapse, with cartilage rings providing structural support and smooth muscle fibers allowing for adjustments in diameter as needed.