Thyroid hormones (T 4 and T 3) are produced by the follicular cells of the thyroid gland and are regulated by TSH made by the thyrotropes of the anterior pituitary gland. The effects of T 4 in vivo are mediated via T 3 (T 4 is converted to T 3 in target tissues). T 3 is 3- to 5- fold more active than T 4.
May is Jewish American Heritage Month The Library of Congress, National Archives and Records Administration, National Endowment for the Humanities, National Gallery of Art, National Park Service and United States Holocaust Memorial Museum join in paying tribute to the generations of Jewish Americans who have helped form the fabric of American history, culture and society.
History of Black History Month Adjust font size: (CNN Student News)-- February marks the beginning of Black History Month, a federally recognized, nation-wide celebration that provides the opportunity for all Americans to reflect on the significant roles that African Americans have played in the shaping of U.S. history.