The results of the present study show that sexual dimorphism in the rat thyroid depends on a difference in the mean volume of thyroid follicular cells, with. Goiter is a condition in which the thyroid gland enlarges. The entire thyroid may grow larger or it may develop one or more small lumps called thyroid nodules. The thyroid gland is an important organ of the endocrine system.
It is located in the front of the neck, just above where the collarbones meet. The gland produces the hormones that control how each cell in the body uses energy. During migration, the thyroid remains connected to the tongue by a narrow channel, the thyroglossal duct. Read about the symptoms of an overactive thyroid (hyperthyroidism) and how this thyroid disorder is diagnosed and managed.
If you don't have enough iodine in your diet, your thyroid enlarges to try to capture as much iodine as it can, so you can produce the right amount of thyroid hormone. Aberrations in prenatal development can lead to various forms of thyroid dysgenesis that can cause congenital hypothyroidism and, if left untreated, this can lead to cretinism. Read how psychological symptoms may accompany thyroid disorders and possible treatment and management options The thyroid gland also produces calcitonin, a hormone that helps regulate the amount of calcium in the blood. Thyroid disorders include hyperthyroidism, hypothyroidism, inflammation of the thyroid (thyroiditis), enlarged thyroid (goiter), thyroid nodules, and thyroid cancer.
In most tetrapod species, there are two paired thyroid glands, that is, the right and left lobes are not joined. The thyroid is near the front of the neck and is located against and around the front of the larynx and trachea. This study was designed to explain whether sex-dependent differences in thyroid gland structure in adult male and female rats depend on quantitative or qualitative changes in thyroid follicular cells. Arterial blood is supplied to the thyroid from the superior thyroid artery, a branch of the external carotid artery, and the lower thyroid artery, a branch of the thyrocervical trunk, and sometimes by an anatomical variant, the imthyroid artery, which has a variable origin.
Chronic thyroiditis (Hashimoto's disease) is a persistent inflammation of the thyroid that develops slowly and often leads to hypothyroidism, a decreased function of the thyroid gland. Goiter can be a general enlargement of the thyroid or it can be the result of irregular cell growth that forms one or more lumps (nodules) in the thyroid. Most goiters are painless, but if you have thyroiditis (inflammation of the thyroid gland), it can be painful. In embryo development, at 3-4 weeks of gestational age, the thyroid gland appears as an epithelial proliferation in the pharyngeal floor at the base of the tongue between the odd tubercle and the copula linguae.
The effects of calcitonin are the opposite of those of parathyroid hormone (PTH) produced in the parathyroid glands.