Parafolliculars gland of thyroid developed from
**Core Concept**
The parafollicular cells of the thyroid gland, also known as C cells, are a type of endocrine cell that plays a crucial role in the production of calcitonin, a hormone involved in calcium homeostasis. These cells are distinct from the follicular cells of the thyroid, which produce thyroid hormones. The development of parafollicular cells is a critical aspect of thyroid gland embryology.
**Why the Correct Answer is Right**
The parafollicular cells of the thyroid gland develop from the ultimopharyngeal body, a group of cells that originate from the neural crest. During embryonic development, the neural crest cells migrate to their final destinations, where they differentiate into various types of cells, including parafollicular cells. The ultimopharyngeal body is a key structure in the development of the parafollicular cells, and its proper formation and migration are essential for the normal development of the thyroid gland.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because parafollicular cells do not develop from the pharyngeal pouches, which give rise to other structures such as the thymus and parathyroid glands.
**Option B:** This option is incorrect because the parafollicular cells do not develop from the neural tube, which gives rise to the central nervous system.
**Option C:** This option is incorrect because the parafollicular cells do not develop from the mesoderm, which gives rise to various other tissues and organs.
**Clinical Pearl / High-Yield Fact**
It is essential to remember that the parafollicular cells of the thyroid gland are distinct from the follicular cells and have a unique embryological origin. This knowledge is crucial for understanding the development and function of the thyroid gland.
**Correct Answer:** D.