Branches of primary bronchi
Upon entering the lung at the hilum, primary bronchi branch to form secondary (lobar) bronchi, two to the left lung and three to the right lung. Cartilage rings are replaced by cartilage plates but mixed glands persist. This image shows branches of a secondary bronchus, called tertiary or segmental bronchi, also with cartilage plates and mixed glands in their wall. Large pulmonary arteries and veins lie adjacent to these passageways. Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like these bronchi, are surrounded by alveoli. The primary bronchus along with the pulmonary and bronchial vessels form the root of the lung. 10x
Bronchial branches
Upon entering the lung at the hilum, primary bronchi branch to form secondary (lobar) bronchi, two to the left lung and three to the right lung. Cartilage rings are replaced by cartilage plates but mixed glands persist. This image shows branches of a secondary bronchus, called tertiary or segmental bronchi, also with cartilage plates and mixed glands in their wall. Large pulmonary arteries and veins lie adjacent to these passageways. Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like these bronchi, are surrounded by alveoli. The primary bronchus along with the pulmonary and bronchial vessels form the root of the lung. 10x
- Cartilage plates
Upon entering the lung at the hilum, primary bronchi branch to form secondary (lobar) bronchi, two to the left lung and three to the right lung. Cartilage rings are replaced by cartilage plates but mixed glands persist. This image shows branches of a secondary bronchus, called tertiary or segmental bronchi, also with cartilage plates and mixed glands in their wall. Large pulmonary arteries and veins lie adjacent to these passageways. Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like these bronchi, are surrounded by alveoli. The primary bronchus along with the pulmonary and bronchial vessels form the root of the lung. 10x
- Mixed glands
Upon entering the lung at the hilum, primary bronchi branch to form secondary (lobar) bronchi, two to the left lung and three to the right lung. Cartilage rings are replaced by cartilage plates but mixed glands persist. This image shows branches of a secondary bronchus, called tertiary or segmental bronchi, also with cartilage plates and mixed glands in their wall. Large pulmonary arteries and veins lie adjacent to these passageways. Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like these bronchi, are surrounded by alveoli. The primary bronchus along with the pulmonary and bronchial vessels form the root of the lung. 10x
Pulmonary vessels
Upon entering the lung at the hilum, primary bronchi branch to form secondary (lobar) bronchi, two to the left lung and three to the right lung. Cartilage rings are replaced by cartilage plates but mixed glands persist. This image shows branches of a secondary bronchus, called tertiary or segmental bronchi, also with cartilage plates and mixed glands in their wall. Large pulmonary arteries and veins lie adjacent to these passageways. Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like these bronchi, are surrounded by alveoli. The primary bronchus along with the pulmonary and bronchial vessels form the root of the lung. 10x
Bronchioles >
Bronchi gradually transition to from bronchioles which are also components of the intrapulmonary conducting system but lack cartilage plates.
Alveoli >
Millions of alveoli comprise the lung proper, so all intrapulmonary structures, like are surrounded by alveoli. Alveoli are cup-shaped and thus in section, some may appear as closed spaces.
