Skeletal muscles are named according to any of these: size, shape,
location, action, number of attachments, direction of its fibers, or
combinations of the above. Examples:
• Pectoralis major: named for size and location; large size, located in chest
• Deltoid: named for shape; shaped like a triangle
• Extensor digitorum: named for action; extends digits (fingers, toes)
• Biceps brachii: named for number of attachments and location; has origins/heads, and is found in the arm (brachium)
• Sternocleidomastoid: named for attachments; attaches to sternum,
clavicle, and mastoid process
• External oblique: named for location and direction of fibers; located
near outside of body, and fibers run at a slant