Parafollicular cells, also known as C cells, are specialized neuroendocrine cells located within the thyroid gland. Their primary function is the production and secretion of calcitonin, a hormone crucial for regulating calcium levels in the blood. These cells reside in the connective tissue adjacent to the thyroid follicles, distinguishing them from the follicular cells responsible for thyroid hormone production.
Key Characteristics of Parafollicular Cells:
- Location: Situated within the thyroid gland, adjacent to the thyroid follicles.
- Function: Primarily secrete calcitonin, a hormone involved in calcium homeostasis.
- Origin: Derived from neural crest cells.
- Clinical Significance: Medullary thyroid cancer (MTC) originates from these cells. MTC is a rare form of thyroid cancer.
Calcitonin's Role in Calcium Regulation:
Calcitonin, produced by parafollicular cells, plays a vital role in maintaining calcium balance. It primarily acts to lower blood calcium levels by inhibiting bone resorption (breakdown of bone tissue) and promoting calcium excretion by the kidneys.
Medullary Thyroid Cancer (MTC):
Medullary thyroid cancer (MTC) is a cancer arising from the parafollicular cells (C cells). This type of cancer is characterized by the production of calcitonin and other hormones. Early diagnosis and treatment are vital for improved outcomes.
In Summary:
Parafollicular cells are essential components of the thyroid gland, playing a crucial role in calcium regulation through calcitonin secretion. Their importance extends to their connection with the development of medullary thyroid cancer.
