connective The outer layer of a blood vessel (artery or vein) is called the tunica externa or tunica adventitia.See http://training.seer.cancer.gov/module_anatomy/unit7_3_ca â¦ rdvasc_blood1_classification.html pericardium is the layer of the blood vessel that is made of tough  connective tissue.onnective The outer layer of a blood vessel (artery or vein) is called the tunica externa or tunica adventitia.
As of June 2000, the fastest running human is Michael Johnson, the American track and field star who on August 1, 1996 set the world record of running 200 meters in 19.32 seconds.
Update: Jamaican sprinter Asafa Powell is the fastest 100 meter sprinter right now. I'm just wondering if anybody what the top speed of a man running at any point in a race would be even if he didn't win it. Update 2: List of fastest men. http://www.cbc.ca/sports/columns/newsmak...