Histomorphological Study of Thymus in Local Chicken " Gallus gallus domesticus "

Abstract

A total number of ten healthy normal chickens from the local breed of both sexes and different ages were used to show the distinctive histological and morphological architecture of the thymus, the morphological study included the location, shape, boundaries and color, for this purpose ten samples of the chicken thymus were used after the birds were killed either by halal method or by euthanasia then thymic samples were treated with the routine histological technique. Morphologically the thymus gland was a paired gland, consisted of two halves, each half was situated along either side of the neck till the entrance of thoracic region in parallel to the common carotid artery, jugular vein, trachea and esophagus and each half contained a number of lobes ranged between 6-8 of flattened shape, while histologically the gland enclosed by a thin connective tissue capsule from which numerous fine septa of connective tissue originated and divided it into moderately separated lobules, the septa contained blood vessels, each lobule had an outer cortex and central medulla without any mark of isolation. Cortex contained a densely packed lymphocytes of small and medium size making it give the impression of appearing deeply basophilic in contrast to the pale eosinophilic medulla which showing reticuloepithelial cells with smaller amount of lymphocytes and acidophilic cytoplasm. The reticuloepithelial cells were lesser in the cortex and numerous in the medulla, which aggregate together thus creating the formation of Hassall's corpuscles.