A normal adult thyroid gland weighs 10 to 20 g and receives blood from bilateral superior and inferior thyroid arteries and a small artery called the thyroid ima. The thyroid secretes two hormones. Thyroxine (T 4) makes about 90% of hormone production, and triiodothyronine (T 3) produces the other 10%.
Fast Growing Cold Hardy Tree. - Grows up to 5 ft per year! The Quaking Aspen is well known for thriving in cold climates and poor soil... but it's also a brightly colored tree with many desirable characteristics.
Many of these trees may be even older than their listed ages, but the oldest wood in the tree has rotted away. For some old trees, so much of the centre is missing that their age cannot be directly determined. Instead, estimates are made based on the tree's size and presumed growth rate. colony of 47,000 quaking aspen trees (nicknamed  Pando ), covering 106 acres (43 ha) in the Fishlake National Forest of Utah, is considered one of the oldest and largest organisms in the world.