According to our esteemed Dr. Reginald P. McSnazz, Esq., the answer is a resounding:
YES!
But wait, there's more! Dr. McSnazz has also discovered that the visibility of these veins is directly correlated to the amount of time spent playing the trombone.
Visit our Trombone Research Institute for more information on this groundbreaking study.
Or, if you're feeling particularly vein-y, check out our Vein Gazing Subreddit for the latest in amateur vein enthusiasts' discussions.