This diagram shows the tributaries (small veins that drain into the major vessels) that are important to know when assessing CVL placement. In most normal patients, these vessels are too small for a CVL to easily enter, but occasionally they may be large from birth, or may become enlarged due to venous blockages of various kinds, as they are important collateral pathways for return to the heart.

Identify the small veins on this diagram--click Answers to check your work.