The difference between tonsils and thyroid

Tonsils and thyroid are completely different organs. Tonsils are located in the throat of the human body and are connected to the outside world, while the thyroid is an endocrine organ. Tonsils produce antibodies to resist viruses in childhood, but their role in the human body is not obvious after adulthood. However, the thyroid gland is the most important organ for secreting hormones in the human body and is an important part of the body's homeostasis. In fact, there is no obvious relationship between the two, but they can be distinguished from their external appearance.

The palatine tonsils are a pair of flat oval lymphoid organs located in the tonsillar fossa. Tonsillar fossa: a triangular depression in the lateral wall of the oropharynx between the palatopharyngeal and palatoglossal arches. The mucosal epithelium sinks into the substance to form a non-depressed pit, called the tonsillar pit. The anterior and lower part of the tonsil is covered by the palatoglossal arch, and the uncovered upper part is surrounded by the tonsillar capsule composed of connective tissue, which is connected to the pharyngeal muscles only by loose connective tissue. This is often the site of peritonsillar abscess formation. The pharyngeal lymphatic ring is composed of the palatine tonsils, pharyngeal tonsils, Eustachian tonsils, and lingual tonsils.

Tonsils can produce lymphocytes and antibodies, so they have anti-bacterial and anti-viral defense functions. The pharynx is the only way for food and air to pass through and is prone to hiding germs and foreign objects if it is frequently touched. The rich lymphatic tissue and tonsils in the pharynx perform the task of defending and protecting this special area of ​​the body. However, this area is also susceptible to infection and invasion by bacteria such as hemolytic streptococci, staphylococci and pneumococci. These bacteria are normally found in the crypts of the human pharynx and tonsils. Under normal circumstances, due to the integrity of the tonsil surface epithelium and the continuous secretion of mucous glands, bacteria can be discharged from the crypt opening along with the shed epithelial cells, thus maintaining the health of the body. When the body's resistance is reduced due to excessive fatigue, cold, etc., the epithelial defense function is weakened, and the glandular secretion function is reduced, the tonsils will be infected by bacteria and become inflamed. If tonsillitis recurs and has adverse effects on the whole body, the tonsils should be removed surgically after careful consideration of the consequences.

The thyroid gland is a very important gland in vertebrates and is an endocrine organ. In mammals it is located below the thyroid cartilage in the neck, on both sides of the trachea. The human thyroid gland is shaped like a butterfly and is like a shield, hence the name. The thyroid gland controls how quickly energy is used, makes proteins, and regulates the body's sensitivity to other hormones. The thyroid gland regulates these responses by producing thyroxine, triiodothyronine (T3) and thyroxine, also known as tetraiodothyronine (T4). Both regulate metabolism, growth rate, and regulate other body systems. T3 and T4 are synthesized from iodine and tyrosine. The thyroid gland also produces calcitonin, which regulates calcium balance in the body.

The thyroid gland is supplied with blood by a pair of superior and inferior thyroid arteries. The superior thyroid artery arises from the external carotid artery or the common carotid artery, and descends with the external branch of the superior laryngeal nerve to 1 to 2 cm above the upper pole of the thyroid gland, where it divides into 2 to 3 glandular branches that are distributed throughout the gland. The inferior thyroid artery originates from the thyrocervical trunk, passes behind the common carotid artery to the back of the left and right lobes of the thyroid gland, and branches into the gland. The inferior thyroid artery is closely related to the recurrent laryngeal nerve. The left artery is mostly located in front of the left recurrent laryngeal nerve, and the right artery runs behind the right recurrent laryngeal nerve; however, it is common for the branches of the artery to cross the nerve. In addition to the two arteries mentioned above, the inferior thyroid artery (also called the thyroid azygos artery) can be seen, which originates from the brachiocephalic trunk, common carotid artery or internal thoracic artery, or directly from the aortic arch and is distributed to the lower part of the gland. The veins of the thyroid gland anastomose into a plexus on the surface of the gland, and are drained by three pairs of thyroid veins: the superior, middle, and inferior thyroid veins, which flow into the internal jugular vein and the brachiocephalic vein respectively. The thyroid gland is an organ with extremely rich blood vessels. In the anterior neck area of ​​patients with diffuse toxic goiter, murmurs can often be heard or tremors can be felt. The thyroid gland receives dual innervation from sympathetic and parasympathetic nerves, the former mainly from postganglionic fibers of the cervical sympathetic ganglia and the latter from the vagus nerve.