Here is a great web page from Dr. Robert Droual, Professor of Anatomy & Physiology at Modesto Junior College, listing muscles, locations of origin and insertion, and actions of the muscles.
I hope you find the my thoughts on these images helpful!
Of particular interest to wind/brass players and vocalists:
Muscles at the Floor of the Mouth
These muscles elevate the hyoid bone and move the tongue back during swallowing and are NOT used while playing or singing. Check out these muscles which restrict tone production and breathing!
Muscles of Facial ExpressionThese muscles move skin rather than a joint when they contract. They control minute movements affecting embouchure and tonal control. Try experimenting with gentle contractions and releases of individual muscles and notice the effects on your tone.
- Flutists: experiment with simultaneous gentle contractions of Depressor labii inferioris, depressor and anguli oris, zygomatic major and minor, and levator labii superioris to free the tongue and lips.
- This is what I often call a "square embouchure. See this post for more info.
Muscles of Mastication
Wind and brass players should take particular care to avoid tensing the muscles of mastication while playing. It is amazing how much simply visualizing these muscles and focusing on relaxing them improves tone!