Morphology of the Spleen in the Camel's Fetus (Camelus dromedarius): Gross Anatomy, Histology and Scanning Electron Microscopic Studies

The spleen is essential for immunological responses to infections that are carried in the blood. The study aimed to investigate the gross anatomy, topography, histology and scanning electron microscopy of the spleen in the dromedary camel fetus (Camelus dromedarius). Fifteen camel foetuses aged 87–418 days were used to examine the prenatal development of the spleen. Standard anatomical, histological, and scanning electron microscopy procedures were applied. Anatomically, the spleen was situated medially to the ribs, caudally to the stomach, and on the caudolateral side of the abdominal cavity. It had C-shaped surfaces with rough surfaces and serrated edges. In the first and second trimesters, the spleen was dark brown and grayish in the third trimester. Histologically, the capsule was made of very thin mesenchyme connective tissue, and the parenchyma had a sporadic distribution of many cell types in the first trimester. The capsule displayed thick, dense, irregular connective tissue with descending trabeculae made up of collagen fibers and bundles of smooth muscle fibres in the second and third trimesters. The parenchyma in the second and third trimesters was presented as white and red pulps. Megakaryocytes were detected in all samples. Scanning electron microscopy revealed that the spleen is lined with mesothelial cells separated by reticular connective tissue fibers. The reticular cells in the cordal gaps, marginal zones, and parietal sheath were relatively small in the first trimester of gestation. In the second and third trimesters, the reticular cells formed a network where dendritic macrophages and lymphoblasts were present. Medium-sized and tiny lymphocytes were seen. The results revealed that the spleen of the dromedary camel fetus was shown to have well-developed characteristics in the second and third trimesters of gestation. Also, the development of the camel’s spleen was comparable to that of other mammalian species but with unique traits and characteristics.