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.
An acre is a measure of land area in Imperial units or U.S. customary units. It is equal to 43 560 square feet, 4840 square yards, or 160 square rods. The precise meaning of this depends on the exact definition adopted for a foot: the international acre is 4 046.856 422 4 m (for the UK, see).he SI derived unit for area is the square meter. 1 square meter is equal to 0.000247105381467 acre, or 10.7639104167 square feet. Note that rounding errors may occur, so always check the results.