The bronchi enter the lung and branch out to form the bronchial tree. The bronchi divide into smaller bronchioles, which terminate into alveoli. An alveolus is composed of respiratory tissue and is the site of gas exchange in the lung. The alveoli are covered in surfactant, a fluid which reduces the surface tension of the alveoli, allowing it to expand and recoil with each inspiration. The blood supply to the lungs is from two sources: the pulmonary vessels and the bronchial vessels. The bronchial vessels support the nonrespiratory tissue and the pulmonary vessels provide support to the respiratory tissue.🏁

The bronchi enter the lung and branch out to form the bronchial tree. The bronchi divide into smaller bronchioles, which terminate into alveoli. An alveolus is composed of respiratory tissue and is the site of gas exchange in the lung. The alveoli are covered in surfactant, a fluid which reduces the surface tension of the alveoli, allowing it to expand and recoil with each inspiration. The blood supply to the lungs is from two sources: the pulmonary vessels and the bronchial vessels. The bronchial vessels support the nonrespiratory tissue and the pulmonary vessels provide support to the respiratory tissue.🏁