MRCP UK EXAMINATIONS

Detailed explanation-1: -Bronchioles lack supporting cartilage skeletons and have a diameter of around 1 mm. They are initially ciliated and graduate to the simple columnar epithelium and their lining cells no longer contain mucous producing cells.

Detailed explanation-2: -BRONCHIOLES: The bronchioles are thin, hollow tubes that contain smooth muscle and can contract and relax, unlike the bronchi they do not have any cartilage rings. Air flows from the bronchi to the bronchioles, where the air then reaches the end of the airway which terminates at the alveoli.

Detailed explanation-3: -The tertiary bronchi subdivide into the bronchioles (respiratory bronchioles). They are histologically distinct from the tertiary bronchi in that their walls do not have hyaline cartilage and they have club cells in their epithelial lining.

Detailed explanation-4: -Terminal Bronchioles. This is the last part of the conducting portion of the respiratory system, and has the smallest diameter of all (less than 1mm). There is no cartilage, or glands, some smooth muscle is still present, there are no goblet cells. The epithelium is either columnar or cuboidal.

Detailed explanation-5: -Bronchioles. The bronchioles are the final air conductors, and by definition, lack cartilage altogether (and are therefore sometimes referred to as membranous) (Fig. 1.11). The bronchioles have no alveoli; alveoli are acquired more distally in the pulmonary acinus.