What do you think this picture represents? Does it show interconnected pipes of a complex plumbing system? A maze of underground passageways in an ant hill? Actually, it’s a microscopic image of vertebrate blood vessels.
Blood vessels are part of the circulatory system, the “highway” system of the human body that transports materials to all of its cells. Red blood cells carry some of these materials, so they are a little like trucks on a highway. In this chapter, you will learn more about blood vessels, red blood cells, and other structures of the circulatory system.
Jiulin Du. www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fimage.pbio.v10.i08#abstract0. CC BY 2.5.