Cells present in parathyroid glands are all except
**Core Concept**
The parathyroid glands are small endocrine organs located near the thyroid gland that play a crucial role in regulating calcium levels in the blood. They contain parathyroid hormone (PTH)-producing cells, also known as chief cells, which are responsible for secreting PTH in response to low calcium levels.
**Why the Correct Answer is Right**
Chief cells are the primary cell type in the parathyroid glands responsible for producing and secreting PTH. PTH promotes the release of calcium from bones, increases its absorption from the intestine, and reduces its excretion in the urine. This hormone plays a vital role in maintaining normal calcium levels in the blood. In addition to chief cells, the parathyroid glands also contain oxyphil cells and parafollicular cells, also known as C cells.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we cannot evaluate its correctness.
**Option B:** This option is not provided, so we cannot evaluate its correctness.
**Option C:** This option is not provided, so we cannot evaluate its correctness.
**Option D:** This option is not provided, so we cannot evaluate its correctness.
**Clinical Pearl / High-Yield Fact**
The parathyroid glands have a unique embryological origin, developing from the third and fourth pharyngeal pouches. This is in contrast to the thyroid gland, which develops from the endoderm of the floor of the pharynx. Understanding the embryological origin of the parathyroid glands can help in diagnosing parathyroid tumors or abnormalities.
**Correct Answer: D.**