Blood Vessels and Nerves of the
Lung
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The lungs | Main Anatomy Index | The
abdominal walls
Last updated 30 March 2006
Arteries, Veins and Innervation of the Lungs
Arterial Supply of the Lungs
The Pulmonary Arteries
- These arise from the pulmonary trunk and distribute deoxygenated blood.
- The right and left pulmonary arteries pass to the corresponding root of the lung and give off a
branch to the superior lobe before entering the hilum.
- There is a branch of this artery to each lobe, bronchopulmonary segment, and lobule of
the lung.
The Bronchial Arteries
- These supply blood to the connective tissue of the bronchial tree.
- The two left bronchial arteries arise from the superior part of the thoracic aorta.
- The single right bronchial artery often arises as a
common trunk with the 3rd (or 5th) posterior
intercostal artery, or from the superior left bronchial
artery.
Venous Drainage of the
Lungs
The Pulmonary Veins
- These carry oxygenated blood back to the left atrium of the heart.
- A main vein drains each bronchopulmonary segment,
usually on the anterior surface of each corresponding bronchus.
- The right superior and left superior pulmonary veins
drain the superior and middle and superior lobes of their respective lungs.
- The right and left inferior pulmonary veins each drain
the inferior lobe of their respective lungs.
The Bronchial Veins
- These only drain the part of the blood delivered by the bronchial arteries to the
bronchial tree.
- The right bronchial vein drains into the azygos vein.
- The left bronchial vein drains into the accessory hemiazygos vein or into
the left superior intercostal vein.
Innervation of
the Lungs and Pleura
- The lungs and pleura are innervated by the anterior and posterior
pulmonary plexuses.
- These are located anterior and posterior to the root of
the lung.
- They are mixed plexuses containing vagal
(parasympathetic) and sympathetic fibres.
Vagus Nerve (parasympathetic)
Efferent fibres
- Motor to the smooth muscle of the bronchial tree (bronchoconstrictor).
- Inhibitor to the pulmonary vessels (vasodilator).
- Secretor to the glands of the bronchial tree (secretomotor).
Afferent fibres
- Sensory to the respiratory epithelium (touch and pain) and to the branches of the
bronchial tree (stretch).
Sympathetic Fibres (sympathetic)
Efferent fibres
- Inhibitors of the bronchial tree (bronchodilator).
- Motor to the pulmonary vessels (vasoconstrictor).
- Inhibitor to the glands of the bronchial tree.
Afferent fibres
