The thyroid gland is a butterfly-shaped gland that sits low on the front of the neck and produces thyroid hormone. The thyroid gland is located below Adam’s apple, along the front of the windpipe, and is a butterfly-shaped organ. The thyroid gland is divided into two side lobes that are connected by an isthmus in the middle. The thyroid does not produce any symptoms when it is at its normal size. The thyroid is also a passageway for nerves that are important for vocal quality.
Thyroid Gland
Thyroid hormones are a group of hormones produced by the thyroid gland that are collectively referred to as thyroid hormones. In addition to their effects on metabolism, thyroid hormones also have an impact on growth and development, as well as body temperature. Thyroid hormone levels must be maintained at optimal levels during childhood and adolescence to ensure proper brain development.
Location
When viewed from the front of the neck, the thyroid is positioned near the larynx and trachea, where it lies against and around them. The thyroid cartilage and cricoid cartilage are located just above and below the thyroid gland, respectively. In humans, the tracheal isthmus extends from the second to third rings of the trachea, with the uppermost part of the lobes extending to the thyroid cartilage and the lowermost part around the fourth to sixth tracheal rings. The isthmus is divided into two lobes, each of which has a distinct shape.
Hormones
It produces three hormones: two thyroid hormones – triiodothyronine (T3) and thyroxine (T4) – and calcitonin (a peptide hormone), which is produced by the parathyroid gland. Thyroid hormones have an effect on the rate of metabolism and protein synthesis, as well as on growth and development in children. It is the anterior pituitary gland that secretes TSH, which regulates the secretion of the two thyroid hormones. Thyroid-stimulating hormone (TSH) regulates the secretion of the two thyroid hormones. Thyrotropin-releasing hormone (TRH) is a hormone that is produced by the hypothalamus and is now responsible for regulating TSH.
The thyroid gland begins to develop in the floor of the pharynx at the base of the tongue at 3–4 weeks of pregnancy; it then descends in front of the pharyngeal gut, and eventually migrates to the base of the neck over the next few weeks. During migration, the thyroid is still connected to the tongue by a narrow canal known as the thyroglossal duct, which is located between the two organs. The thyroglossal duct begins to degenerate at the end of the fifth week, and the detached thyroid migrates to its final position over the next two weeks.
Euthyroid
The term “euthyroid” refers to a state of normal thyroid function in the body, and it is used to describe this state. In addition to hyperthyroidism and hypothyroidism, thyroid inflammation (thyroiditis), thyroid enlargement (goitre), thyroid nodules, and thyroid cancer are all conditions that can affect the thyroid gland. When a person has hyperthyroidism, they produce an excessive amount of thyroid hormones. The most common cause of hyperthyroidism is the autoimmune disorder Graves’ disease. When there is insufficient secretion of thyroid hormones, this is referred to as hypothyroidism, and the most common cause is a lack of iodine in the diet. In iodine-deficient areas, hypothyroidism secondary to iodine deficiency is the most common cause of preventable intellectual disability in children under the age of 5. Hypothyroidism is most commonly caused by Hashimoto’s thyroiditis, an autoimmune disorder that affects people who live in iodine-deficient areas.
Throughout the late nineteenth and twentieth centuries, advances in understanding of the thyroid, its biochemistry, and the disorders that can occur were made. Through the mid-twentieth century, many modern treatments and investigative modalities were developed, including refinement of surgical techniques for thyroid removal (thyroidectomy) for the treatment of goitre; the use of radioactive iodine and thiouracil for the treatment of Graves’ disease; and fine needle aspiration for the diagnosis of thyroid nodules.
Calcitonin
The thyroid gland also produces the hormone calcitonin, which is important in maintaining healthy calcium levels in the blood. In response to elevated calcium levels in the blood, parafollicular cells produce calcitonin. It works by slowing the release of calcium from bone by inhibiting the activity of osteoclasts, which are the cells that break down bone. Because bone is constantly being reabsorbed by osteoclasts and being created by osteoblasts, calcitonin is an effective stimulator of calcium transport into bone. When calcitonin is present, its effects are diametrically opposed to those of parathyroid hormone (PTH), which is produced by the parathyroid glands. However, calcitonin appears to be far less important than parathyroid hormone (PTH), as calcium metabolism continues to be clinically normal after removal of the thyroid (thyroidectomy), but not after removal of the parathyroid glands.
Conclusion
The thyroid, also known as the thyroid gland, is an endocrine gland that is found in vertebrates. It is located in the neck of humans and is made up of two lobes that are connected. During development, the thyroid isthmus, a thin band of tissue connecting the lower two-thirds of the lobes, was discovered. In the front of the neck, below the Adam’s apple, is where the thyroid gland can be found. Observed under a microscope, the thyroid gland’s functional unit is represented by the spherical thyroid follicle, which is lined with follicular cells (thyrocytes) and occasional parafollicular cells and surrounds a lumen that contains colloid.