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.
Leroy Burrell (United States) â Fastest Time: 9.85 seconds. Burrell had twice set the world record in the 100 metres with a 9.90 in 1991 and a 9.85 in 1994. 8. Justin Gatlin (United States) â Fastest Time: 9.85 seconds. Gatlinâs fastest time was set at the 2004 Olympics with a gold metal winning 9.85 second run. 9. Olusoji Fasuba (Nigeria) â Fastest Time: 9.85 seconds. Fasuba holds the African 100 metre sprinting mark with a 9.85 at the Doha Grand Prix in 2006.