Guido of Arezzo
In the 12th century, a development in teaching and learning music in a more efficient manner had arisen. Guido of Arezzo's alleged development of the Guidonian hand, more than a hundred years after his death, allowed for musicians to label a specific joint or fingertip with the gamut (also referred to as the hexachord in the modern era). Using specific joints of the hand and fingertips transformed the way one would learn and memorize solmization syllables. Not only did the Guidonian hand become a standard use in preparing music in the 12th century, its popularity grew more widespread well into the 17th and 18th century. The knowledge and use of the Guidonian hand would allow a musician to simply transpose, identify intervals, and aid in use of notation and the creation of new music. Musicians were able to sing and memorize longer sections of music and counterpoint during performances and the amount of time spent diminished dramatically.
Thyroid
In 1500 polymath Leonardo da Vinci provides the first illustration of the thyroid. In 1543 Anatomist Andreas Vesalius gave the first anatomic description and illustration of the gland. In 1656 the thyroid received its name, by the anatomist Thomas Wharton. The gland was named thyroid, meaning shield, as its shape resembled the shields commonly used in Ancient Greece. The English name "thyroid gland" is derived from the medical Latin used by Wharton – "glandula thyreoidea". "Glandula" means "gland" in Latin, and "thyreoidea" can be traced back to the Ancient Greek word θυρεοειδής, meaning "shield-like"/"shield-shaped".