March 25, 2013 @ BrainPickings
Zooming in on the microcosm of our own bodies and their curious behaviors, Jill Conte considers why we blush:
The ruddy or darkened hue of a blush occurs when muscles in the walls of blood vessels within the skin relax and allow more blood to flow. Interestingly, the skin of the blush region contains more blood vessels than do other parts of the body. These vessels are also larger and closer to the surface, which indicates a possible relationship among physiology, emotion, and social communication. While it is known that blood flow to the skin, which serves to feed cells and regulate surface body temperature, is controlled by the sympathetic nervous system, the exact mechanism by which this process is activated specifically to produce a blush remains unknown.