Left upper lobe
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:
- deoxygenated blood from the left upper lobar pulmonary artery
- oxygenated blood from branches of the left bronchial arteries
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
- parasympathetic fibers from the vagus nerve (CN X)
- sympathetic fibers from the paravertebral sympathetic trunks
Related pathology
Related Radiopaedia articles
Anatomy: Thoracic
- thoracic skeleton
- thoracic cage
- thoracic spine
- articulations
- muscles of the thorax
- diaphragm
- intercostal space
- intercostal muscles
- variant anatomy
- spaces of the thorax
- thoracic viscera
- tracheobronchial tree
-
lungs
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
- left lung
- right lung
- variant anatomy
- lung parenchyma
- hilum
- pleura
-
bronchopulmonary segmental anatomy (Boyden Classification) (mnemonic)
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heart
- cardiac chambers
- heart valves
- pectinate muscles
- cardiac fibrous skeleton
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coronary arteries
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- myocardial segments
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left main coronary artery (LMCA)
- ramus intermedius artery (RI)
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circumflex artery (LCx)
- obtuse marginal branches (OM1, OM2, etc))
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left anterior descending artery (LAD)
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- septal perforators (S1, S2, etc)
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right coronary artery (RCA)
- conus artery
- sinoatrial nodal artery
- acute marginal branches (AM1, AM2, etc)
- inferior interventricular artery (PDA)
- posterior left ventricular artery (PLV)
- congenital anomalies
- innervation of the heart
- fetal circulation
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pericardium
- pericardial space
- oblique pericardial sinus
- transverse pericardial sinus
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pericardial recesses
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- inferior vena cava (IVC)
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coronary veins
- cardiac veins which drain into the coronary sinus
- great cardiac vein
- middle cardiac vein
- small cardiac vein
- posterior vein of the left ventricle
- vein of Marshall (oblique vein of the left atrium)
- anterior cardiac veins
- venae cordis minimae (smallest cardiac veins or thebesian veins)
- cardiac veins which drain into the coronary sinus
- pulmonary veins
- thoracoepigastric vein
- lymphatics
- innervation of the thorax