( 2 ) affording multiple anchor points for skeletal muscle attachment ( as with the sacrum ) , and maintaining pharynx and trachea support , and tongue attachment ( such as the hyoid bone ) . Irregular bones serve various purposes in the body , such as protection of nervous tissue ( such as the vertebrae protect the spinal cord ) , affording multiple anchor points for skeletal muscle attachment ( as with the sacrum ) , and maintaining pharynx and trachea support , and tongue attachment ( such as the hyoid bone ) .