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.
Usain St. Leo Bolt, (/ËjuËseÉªn/ ; born 21 August 1986) is a Jamaican sprinter. Regarded as the fastest person ever, he is the first man to hold both the 100 metres and 200 metres world records since fully automatic time measurements became mandatory in 1977. Along with his teammates, he also set the world record in the 4Ã100 metres relay.