An official Site of the United States federal government. This is how you understand we're Formal. dot gov icon SMART Vocabulary: related words and phrases Substances & structures in your body abductor accessorius acetylcholine ACL ACTH folate follicular foramen foramen ovale fornix myocardium myofibril myofibrillar myofilament myology tegument temporomandibular https://www.youtube.com/watch?v=A07qHOeWON8