The primary function of the thyroid is the production of the iodine-containing thyroid hormones, triiodothyronine (T3) and thyroxine (T4) and the peptide hormone calcitonin. 1  T3 is so named because it contains three atoms of iodine per molecule and T4 contains four atoms of iodine per molecule.
David Livingstone was born on March 19, 1813, in Blantyre, South Lanarkshire, Scotland, and grew up with several siblings in a single tenement room.
The fleet visited towns along the east coast of Africa of what are now Somalia and Kenya and almost reached the Mozambique Channel. On his return to China in 1415, Zheng He brought the envoys of more than 30 states of South and Southeast Asia to pay homage to the Chinese emperor.