ANATOMY: Facial Muscles. Tension first builds on the face, learn to loosen up! The muscles of the face are unique among groups of muscles in the body. While most muscles connect to and move only bones, facial muscles mostly connect bones to skin.
Leonardo da Vinci's depiction of the bones, muscles and tendons of the hand, c.1510-11 http://www.dailymail.co.uk/sciencetech/article-2292206/The-startling-accuracy-Leonardo-da-Vincis-anatomical-sketches-revealed-comparison-modern-medical-scans.html