Where is the thyroid gland?

Almost all vertebrates have a thyroid gland. The thyroid gland is a very important gland in the human body and is an endocrine organ. The thyroid gland plays an important role in human health, such as important immune functions. The human thyroid gland secretes a type of cell called a secretory cell, which produces calcitonin, so it can regulate the body's calcium level. So where is the human thyroid gland located?

Where is the thyroid gland?

The thyroid gland is shaped like an "H", brown-red in color, and consists of two lobes, left and right, connected by an isthmus in the middle. The two side lobes are attached to the outer sides of the lower larynx and the upper trachea, reaching the middle part of the thyroid cartilage and the sixth tracheal cartilage. The isthmus is mostly located in front of the second to fourth tracheal cartilages and is underdeveloped in some people. Sometimes a cone-shaped lobe extends upward from the isthmus. It varies in length, with the longer one reaching the hyoid bone. It is a relic of embryonic development and often gradually degenerates with age, so it is more common in children than in adults.

The thyroid gland is covered with a fibrous capsule, called the thyroid capsule. This capsule extends into the glandular tissue and divides the gland into lobules of varying sizes. The capsule is covered with the deep cervical fascia (pretracheal layer). There is often ligament-like connective tissue connecting the lateral lobes of the thyroid gland and the cricoid cartilage. Therefore, when swallowing, the thyroid gland can move up and down with swallowing.

During puberty, the thyroid gland matures and weighs 15 to 30 grams. The width of each of the two lateral lobes is about 2 cm and the height is 4 to 5 cm. The width of the isthmus is 2 cm and the height is 2 cm. Women's thyroid gland is slightly larger than men's. Under normal circumstances, the thyroid gland is so small and thin that it cannot be seen or felt in the neck. If the thyroid gland can be felt in the neck, even if it cannot be seen, it is considered to be enlarged. This degree of swelling is often physiological, especially during female puberty, and is generally not the result of disease, but it can sometimes be pathological.

Normally most people do not know where the thyroid gland is located, but most people are familiar with "thick neck disease". In fact, "thick neck disease" is an enlarged thyroid gland, which tells that the thyroid gland is located in the neck. To be more specific, you can feel the "Adam's apple" that we usually talk about. The thyroid gland is located about 2 to 3 centimeters below the "Adam's apple" and can move up and down with it when you swallow.