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.
by Chuck Klosterman on July 16, 2011. Allow me to spare you the hyperbole: Usain Bolt is fast. He is, as far as we can tell, the fastest human whoâs ever lived â in 2009, at a race in Berlin, he ran the 100-meter dash is 9.58 seconds. This translates to an average speed of just over 23 mph (with a top speed closer to 30 mph).