The walls of the main, lobar, and segmental bronchi contain progressively lesser amounts of ________.
A) cartilage
B) smooth muscle
C) adipose tissue
D) epithelium
E) skeletal muscle

Question

Quizplus · Accepted Answer

The walls of the bronchi contain cartilage as a supporting structure, but the amount of cartilage decreases as the bronchi become smaller in diameter. Therefore, the walls of the main, lobar, and segmental bronchi contain progressively lesser amounts of cartilage. Smooth muscle, on the other hand, is abundant in the walls of bronchi and helps regulate the diameter of the airways. Adipose tissue and skeletal muscle are not typically found in the walls of bronchi. The epithelium lines the inner surface of the bronchi and is present throughout the respiratory tract. However, the amount or type of epithelium may vary in different parts of the respiratory system.

The Walls of the Main, Lobar, and Segmental Bronchi Contain