FUNCTIONAL-ANATOMY OF BRONCHIAL CIRCULATION OF DOMESTIC-FOWL

  • 1 January 1976
    • journal article
    • research article
    • Vol. 121  (JUL) , 537-550
Abstract
Injection techniques were used to study the origin and distribution of the bronchial circulation of the domestic fowl (Gallus gallus domesticus). The right and left bronchial arteries arise from the bronchoesophageal artery, which is a branch of the right common carotid artery. In contrast to the mammalian bronchial arteries, each bronchial artery in this species of bird is confined to the extrapulmonary part of the primary bronchus. At its caudal end it forms a direct anastomosis of large caliber with a branch of the pulmonary artery within the hilus of the lung. The bronchial artery connects with the systemic circulation at one end and with the pulmonary circulation at the other. Injections of Lycopodium spores into the jugular vein of anesthetized fowls suggest that the direction of blood flow in the bronchial artery is from the pulmonary artery towards the bronchoesophageal artery. The left and right bronchial veins empty into the left and right pulmonary veins. The intrapulmonary part of the primary bronchus is supplied by the pulmonary artery and drained by the pulmonary vein. The atrial smooth muscle bundles of the secondary bronchi and parabronchi are supplied by capillary-like septal venules which drain the exchange tissue, form a network immediately beneath the muscle bundles, and empty into branches of the pulmonary vein. There are no blood vessels actually within the atrial muscle bundles, so presumably the smooth muscle cells in these bundles receive O2 by diffusion from the air in the parabronchial lumen. The arterial supply to the pleura is from esophageal branches of the bronchoesophageal artery, and from small twigs of the internal thoracic artery and intercostal arteries. The pleural venous drainage is into the esophageal veins, intercostal veins and pulmonary veins.