Morphological Peculiarities of the Lumbosacral Region of Cattle Egret (Bublucus ibis) with Special Reference to the Glycogen Body (Corpus gelatinosum)

Abstract

The current study aimed to study morphological peculiarities of of the Lumbosacral Region of Cattle Egret with special reference to the glycogen body. The lumbosacral organ (LSO) is a unique modification in the spinal cord of all birds. Twenty adult cattle egret of both sexes are used to describe the morphological and histological peculiarities of this organ in cattle egret. The synsacrum of these birds was examined by gross, cross-sectional anatomy, Computed Tomography (CT), and transverse histological sections with different stains. The morphological peculiarities of the lumbosacral region of cattle egret includes enlarged vertebral canal in the region of synsacrum. This enlargement is due to the presence of a gelatinous  glycogen body embedded in the rhomboid sinus of the spinal cord. Accessory lobes protrude at the ventrolateral end of the ventral horns in the vertebral canal. Transverse lumbosacral canals similar to semicircular canals above the spinal cord. The spinal cord is fixed to the vertebra by a network of dentate ligaments. Histologically both glycogen body and accessory lobes contain glycogen-containing glia cells. These cells were polygonal with narrow cytoplasmic rim and nucleus pushed to periphery by a central mass of glycogen. The blood capillaries were distributed throughout the glycogen body and accessory lobes. The connective tissue was very scanty except in the vicinity of the blood capillaries and central canal. The accessory lobes contain multipolar neurons scattered between the glia cells. The transverse lumbosacral canals were fluid-filled meningeal tubes that arch dorsally over the spinal cord and open laterally above the accessory lobes. The network of dentate ligaments formed from regular dense fibrous connective tissues mainly collagenous fibers. Therefore this work concluded that the proposition of the anatomical and histological modifications of the lumbosacral region might act as a sense organ of equilibrium control the balanced walking on the ground.