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.
Best known as: The Jamaican sprinter who won 100- and 200-meter gold medals at both the 2008 and 2012 Olympics. Usain Bolt became famous as the world's fastest man in 2008, the year he ran the 100 meters in a spectacular 9.69 seconds at the Beijing Olympic Games. Born in Jamaica, Usain Bolt was a speedster from the start: he was only 15 when he won a gold medal in the 200 meters at the 2002 World Junior Championships.