Primary Bronchi

Lobar Bronchi

The primary left and right bronchiThe large airways that branch from the trachea into the lungs, dividing into smaller bronchioles. are covered in the same pseudostratified columnar epithelium as the trachea. They also have a thick sheet of smooth muscle responsible for bronchoconstriction.  Primary bronchi may have supportive hyaline cartilageThe most abundant cartilage type, found in joints, ribs, and the nose., but not in the fully C-shaped cartilageA flexible connective tissue found in joints, the ear, nose, and rib cage. Cartilage can be of three rings of the trachea.

The primary bronchiThe first branches of the trachea that lead into the lungs. Also called lobar bronchi lead to each lung and divide into secondary or lobar bronchi. The left lung has three lobes. It also has three lobar bronchi. In contrast, the right lung has only two lobes and thus only two lobar bronchi.

Segmental Bronchi

The lobar bronchi divide into tertiary or segmental bronchi. These segmental bronchi serve bronchopulmonary segmentsFunctional units of the lungs, each served by its own tertiary bronchus and blood supply. of the lungs.

As bronchi give way to bronchioles, the diameter decreases as does the thickness of the smooth muscle.