The Thyroid itself secretes three main hormones: 1  Thyroxine contains iodine which is essential for the body's normal growth, and metabolism. 2  Triiodothyronine has similar functions to thyroxine. 3  Calcitonin causes a decrease in the concentration of calcium in the blood.
acre. acre, measure of land area used in the English units of measurement. The acre was originally the area a yoke of oxen could plow in a day and therefore differed in size from one locality to another.It is now fixed as 10 square chains or 160 square rods, i.e., 4,840 sq yd, 43,560 sq ft, or 1/640 sq mi. Share | Cite. acre, measure of land area used in the English units of measurement. The acre was originally the area a yoke of oxen could plow in a day and therefore differed in size from one locality to another. It is now fixed as 10 square chains or 160 square rods, i.e., 4,840 sq yd, 43,560 sq ft, or 1/640 sq mi.
Save. Land may be measured in square feet or acres, depending on the size of the plot. Acres are generally used to delineate rectangular or square plots of land that cover an area too great to view from the ground. Because acres can vary in shape, the outside perimeter of a plot can vary.