Left upper lobe
Citation, DOI & article data
The left upper lobe (LUL) is one of two lobes in the left lung. It is separated from the left lower lobe by the left oblique fissure and subdivided into four bronchopulmonary segments, two of which represent the lingula.
Location and structure
The left upper lobe lies in the upper aspect of the left hemithorax and contains four bronchopulmonary segments:
Like all the pulmonary lobes, it is lined by visceral pleura which reflects at the pulmonary hilum where it is continuous with the parietal pleura. The left upper lobe bronchus arises from the superolateral wall of the left main bronchus to traverse the left hilum into the LUL.
Like all the lobes of the lung, the LUL has dual arterial supply:
- deoxygenated blood from the left upper lobar pulmonary artery
- oxygenated blood from branches of the left bronchial arteries
The superficial subpleural lymphatic plexus drains the lung parenchyma and visceral pleura to the bronchopulmonary (hilar) lymph nodes in the hilum.
The deep bronchopulmonary lymphatic plexus (in the bronchial submucosa and peribronchial interstitium) drains the root of the lung to hilar lymph nodes in the hilum.
The hilar lymph nodes then drain to the tracheobronchial lymph nodes.
- parasympathetic fibers from the vagus nerve (CN X)
- sympathetic fibers from the paravertebral sympathetic trunks