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.
I just dug this newspaper article out of my running scrapbook. AUCKLAND, NEW ZEALAND - AMERICAN STEVE SCOTT, TAKING ADVANTAGE OF A STRAIGHT, DOWNHILL COURSE, RAN THE FASTEST MILE IN TRACK HISTORY SATURDAY, WINNING THE INAUGURAL QUEEN STREET MILE IN 3 MINUTES 31.25 SECONDS.