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.
Months are either 29 or 30 days, corresponding to the 29Â½-day lunar cycle. Years are either 12 or 13 months, corresponding to the 12.4 month solar cycle. The lunar month on the Jewish calendar begins when the first sliver of moon becomes visible after the dark of the moon.In ancient times, the new months used to be determined by observation.he Jewish calendar is based on three astronomical phenomena: the rotation of the Earth about its axis (a day); the revolution of the moon about the Earth (a month); and the revolution of the Earth about the sun (a year).