Histology of the Hindgut of Solitary Locusta (Orthoptera: Acrididae )

Abstract

Hindgut of Solitary has been into its three regions: ileum, colon, and rectum, and each region was studied morphologically, histologically and functionally. Ileal structure has been investigated throughout its length from pyloric valve ( the border between the midgut and the hindgut) to its end ,which marks the border between the ileum and the colon. The 6 layers apical wall of circular muscles were fully described with the longitudinal muscles. The 12 inner ileal epithelial folds consist of columnar cells with microvilli, which suggest that the ileum is involved with nutrition absorption. The 12 ileal folds are close to the inner wall of the proximal circular muscles, but in another locust are projecting inward the lumen centre. But in both structures the subintimal space is clear. The 12 ileal folds become reduced to the smallest in size and less in count. Their reduction continues to the lowest size till they become traces at the end of the ileum. The colon structure shows that the diameter becomes small and the tissue between the layer circular muscles and the 4 thick folds of the colon. The area between the circulat muscles and the inner columnar cells is full of thick longitudinal muscles. The rectal structure shows the 6 large rectal papillae and small rectal pads which grow to replace the rectal papillae. Rectal papillae are involved with mineral and water re-absorption. At the middle rectal area structure shows 6 areas occupied by rectal pads and 6 reduced between rectal areas, which have columnar epithelial cells. Their function is to facilitate the faeces evacuation by their contraction and expanding as they do as articulation. Rectal pads show different type of cells such principal cells, basic cells and junctional cells. Also intrapapillar lumen, tracheae, and also the circular and longitudinal muscles are very clear .