By SoulSurvivorsGaming, writer at creators.co. DC and Marvel have dominated the comic book industry for decades now, causing millions of people to have a beloved list of their favorite superheroes and characters from those universes. Characters including: Batman, Iron Man, Spider-Man, Superman and even Aqualad.
There are three kinds of blood vessels: arteries, veins, and capillaries. Each of these plays a very specific role in the circulation process. Arteries carry oxygenated blood away from the heart. Theyâre tough on the outside but they contain a smooth interior layer of epithelial cells that allows blood to flow easily.
1 The three major types of vessels are arteries, capillaries, and veins. 2  Arteries carry blood away from the heart, veins carry blood toward the heart. 3  Capillaries contact tissue cells and directly serve cellular needs. 4  Arteries and veins are composed of three tunics. 5  tunica interna (tunica intima).