Morphological and Histological Studies on Parathyroid Gland of Adult Male Goat (Capra Hircus)

Abstract

The parathyroid glands are essential endocrine glands as they produce hormones that maintain calcium within the normal level in blood through secretion of parathormone. The removal of parathyroid glands leads to fatal levels of hypocalcemia. The number of parathyroid glands is species specific. The current investigation was performed on 20 healthy freshly slaughtered adult male goats. Fifteen specimens were immediately fixed in 10% buffered neutral formalin, then processed for histological and immunohistochemical examination. Other 5 specimens were handled for transmission electron microscope. The present work was conducted to study the morphological and histological characteristics of parathyroid glands of goat. Parathyroid glands comprised of two pairs, each pair formed from external and internal glands. External parathyroid gland was rounded or oval in shape. Its location was varied in the same animal where it may be located cranial to thyroid gland or beside the submandibular salivary gland. Internal parathyroid gland was embedded inside thyroid tissue. It appeared as pale rounded area at the end of cranial part of the right and left thyroid lobe. The histological findings demonstrated that, each parathyroid gland is surrounded by a thin capsule of dense irregular connective tissue. The glandular parenchyma is divided by short thick septa into ill distinct compartments. Each compartment had numerous numbers of chief cells. The active chief cells were polygonal in shape with oval nuclei. Immuno-histochemical findings revealed that they are positively reacted against chromogranin antibody. Electron microscope revealed that the cytoplasm have abundant mitochondria, rough endoplasmic reticulum, evenly distributed golgi apparatus and numerous secretory granules. On the contrary, the inactive chief cells have more vacuolated cytoplasm which contains less cell organelles.