HISTOMORPHOGENESIS OF PINEAL GLAND IN GOAT FOETUSES

Abstract

Prenatal development of pineal gland in goat was studied using 52 goat foetuses ranging from 1.4cm CRL (24 days of gestation) to 41.5cm CRL (full term). Pineal gland developed during the seventh week as a conical evagination on the caudo-dorsal aspect of the diencephalon and lumen of the third ventricle extended towards the pineal body as the pineal recess. During third month, the stalk was divided into a dorsal lamina continuous with the dorsal commissure and a ventral lamina, continuous with the posterior commissure. A thin connective tissue capsule covered the pineal gland by 76 days of age. The parenchymal cells were arranged in a cord-like manner and there was a central lumen. The neuroglial cells were scattered among the pinealocytes from which they could be distinguished by their smaller and darker nuclei. By 124 days of age, the pineal gland was elongated or ova! in shape. The accessory pineal gland could not be located. Histologically the pineal gland acquired the adult characteristics towards the terminal stages of pregnancy. From the capsule, connective tissue septa penetrated the gland, dividing the parenchyma into small lobules. The parenchyma consisted of pinealocytes and glia! cells scattered throughout in the fibrous network of interstitial tissue, fine blood vessels and nerve fibres. Towards the central portion, the cells were loosely arranged when compared to the periphery and the central lumen disappeared at this stage. The pinealocytes were of two types namely the light and dark cells. Four types of glia! cells could be identified based on the nuclear morphology

Keywords

• pineal gland
• goat
• prenatal development