Left upper lobe

Last revised by Craig Hacking on 14 Oct 2022

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.

    Gross anatomy

    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.

    The LUL is separated from the LLL below and posteriorly by the oblique fissure.

    Arterial supply

    Like all the lobes of the lung, the LUL has dual arterial supply:

    Venous drainage

    Venous drainage of newly oxygenated blood is via the left superior pulmonary vein into the left atrium.

    Left bronchial veins drain into the accessory hemiazygos vein or the
    left superior intercostal vein.

    Lymphatic drainage

    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.


    Innervation is derived from the pulmonary plexus:

    Related pathology

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