I like this picture as it simply and beautifully depicts a very complicated construct. As the nerves course to the surface they serve various functions, based on location, anatomy, and purpose. The autonomic nerves are not a completely separate component, but provide input along their path even to the muscles. However, they dominate at the surface where the majority of neural input to the hypodermis is coming from and going back to the autonomic nervous system (ANS). This makes perfect sense since the skin and superficial tissues are like radar: they are constantly perceiving the surrounding environment in order to make adjustments that support homeostasis (optimal function of an organism). You step outside from a cool office into blistering heat and immediately your superficial blood vessels have to dilate to dissipate heat, or you will become overheated. Used with permission from Dr. Carla Stecco, MD.