Thyroid vertebrates. In fish, it is usually located below the gills and is not always divided into distinct lobes. However, in some teleosts, patches of thyroid tissue are found elsewhere in the body, associated with the kidneys, spleen, heart, or eyes. In tetrapods, the thyroid is always found somewhere in the neck region. In most tetrapod species, there are two paired thyroid glands – that is, the right and left lobes are not joined together. However, there is only ever a single thyroid gland in most mammals, and the shape found in humans is common to many other species. In larval
Desiccated thyroid extract Desiccated thyroid extract Desiccated thyroid or thyroid extract refers to porcine or bovine thyroid glands, dried and powdered for therapeutic use. Animal extract thyroid preparations were developed in the late 19th century, and are still in use today for the treatment of hypothyroidism. This product is sometimes referred to as "natural thyroid", "natural thyroid hormones", "pork thyroid", thyroid USP, thyroid BP, or by the name of a commercial brand, such as "Armour Thyroid" , "NP Thyroid" or "Nature-Throid" & "Westhroid". Desiccated thyroid has been described in the United States Pharmacopoeia for a century as "the cleaned, dried, and powdered thyroid