Organisation and structure of the tracheal and bronchial blood vessels in the dog
Laitinen, A.; Laitinen, L.A.; Moss, R.; Widdicombe, J.G.
Journal of Anatomy 165: 133-140
1989
ISSN/ISBN: 0021-8782 PMID: 17103607 Document Number: 341701
We have studied the tracheal and bronchial microcirculation of dogs. Plastic casts of the vessels were studied by scanning electron microscopy. A dense network of small vessels ran in the trachea and bronchi close to the tracheobronchial lumen around and along the airway wall. The plastic replicas were visualised three-dimensionally as tubes. Under light and transmission electron microscopy, capillaries lay just under the epithelial basement membrane. Small postcapillary venules were found deeper in the mucosa. Arterioles occurred regularly between the cartilaginous plates in the trachea but there were only a few in the tracheobronchial mucosa itself and none was closer than 100 .mu.m to the epithelial basement membrane. The diameter of most vessels in the airway mucosa was less than 30 .mu.m. No arteriovenous anastomoses were seen. Apart from a possible physiological role in conditioning inspired air, the profuse subepithelial microvasculature may act as a means of uptake and distribution of mediators and also as a barrier between the lumen and the airway smooth muscle.