Figure 10

Dorsal view of the lungs and bisecting thoracic aorta. There are numerous prominent small tortuous thin walled blood filled vessels (veins) between the caudal pulmonary pleurae and periaortic mediastinal connective tissue (arrows). They originate as fine hair-like vessels in the pulmonary pleura and anastomose to form larger vessels towards the aortic adventitia where they drain into the azygos and costal veins (not in picture).