The venous blood from lungs is also emptied by 2 sets of veins, viz.

A. Bronchial veins.

B. Pulmonary veins.

Bronchial Veins.

The bronchial veins drain the deoxygenated blood from the bronchial tree and pulmonary tissue. There are 2 bronchial veins on every side:.

A. The right bronchial veins drain into azygos veins.

B. The left bronchial veins drain into hemiazygos vein or left superior intercostal vein.

Pulmonary Veins.

The pulmonary veins drain the oxygenated blood from the lungs. There are just two pulmonary veins on every side.

The pulmonary veins don’t accompany the pulmonary arteries. The tributaries of pulmonary veins are intersegmental, while branches of pulmonary arteries are segmental in distribution.

Points to be noticed

A. All the veins in the body drain deoxygenated blood with the exception of pulmonary veins, which drain the oxygenated blood from the lungs.

B. All the arteries of the body provide oxygenated blood with the exception of pulmonary arteries, which provide deoxygenated blood to the lungs.

C. The bronchial arteries supply nutrients to the bronchial tree, as far as the respiratory bronchioles, i.e., non ¬ respiratory portions of the lungs.

D. The respiratory portions of the lungs are nourished by pulmonary capillary beds and atmospheric air in the alveoli.