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.
The Jewish calendar is based on lunar cycles. Towards the beginning of the moonâs cycle, it appears as a thin crescent. That is the signal for a new Jewish month. The moon grows until it is full, the middle of the month, and then it begins to wane until it cannot be seen. It remains invisible for approximately two daysâand then the thin crescent reappears, and the cycle begins again. The entire cycle takes approximately 29Â½ days.