Regarding intercostal blood vessels:

• A. in each space there are single anterior and posterior intercostal veins
• B. right sided superior intercostal vv drain into the brachiocephalic vein
• C. the second intercostal space does not contain a posterior intercostal artery
• D. all intercostal vv are branches of the descending thoracic aorta
• E. all this is clinically relevant