The trachea divides into the left and right main bronchi (brong′ k ; sing. bronchus, brong′ kŭ s; windpipe), or primary bronchi, each of which connects to a lung. The left main bronchus is morehorizontal than the right main bronchus because it is displaced by the heart (figure 15.5). Foreign objects that enter the trachea usu-ally lodge in the right main bronchus, because it is wider, shorter, and more vertical than the left main bronchus and is more in direct line with the trachea. The main bronchi extend from the trachea to the lungs. Like the trachea, the main bronchi are lined with pseudostratified ciliated columnar epithelium and are supported by C-shaped pieces of cartilage.