Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean; but the atmosphere contained almost no oxygen and so would have been toxic to most modern life including humans.
Euthyroid is the state of having normal thyroid gland function. Examples of a nonfunctioning thyroid gland may be hypothyroidism, hyperthyroidism, or thyroiditis.
parathyroid hormone. or. a hormone hormone,secretory substance carried from one gland or organ of the body via the bloodstream to more or less specific tissues, where it exerts some influence upon the metabolism of the target tissue...... Click the link for more information.