Prenatal Morphological and Morphometric Studies on the pancreas of the camel foetus(CamelusDromedarius)

Abstract

This study aimed at investigating the development of the gross anatomy, histology and morphometry of the pancreas of the camel foetus(CamelusDromedarius). A total of thirty camel foetuses were used in this study. Specimens were collected from Tamboul Slaughterhouse, Sudan. Foetuses were divided into three trimesters according to the gestation period. The pancreas in the first trimester (Crown Vertebral Rump Length (CVRL) 8-17cm, 87-111 days of gestation) had gray colour but in the second(Crown Vertebral Rump Length(CVRL) 45-71cm, 188-259 days of gestation) and third trimester (Crown Vertebral Rump Length. (CVRL) 75-110cm, 270-366 days of gestation) the colour was grayish pink. The pancreas was found to be divided into a body, a right lobe and a left lobe at all trimesters. These divisions could be described as a wide body, a quadrate right lobe and a long tongue-shaped left lobe in the second and the third trimesters. The body of the pancreas was related dorsally to the visceral surface of the liver and caudally to the stomach. It was related cranially to the curvature of the duodenum and ventrally to the spleen. The right lobe was related dorsally to the visceral surface of the liver, medially to the portal vein and laterally to the descending duodenum and ventrally to the transverse colon. The left lobe was related caudodorsally to the stomach, ventrally to the kidney, spleen and cranially to the colon. The pancreas in the second and third trimesters was clearly tubuloacinar and containing a single row of similar pyramidal epithelial cells converging to a central narrow lumen. However, in the first trimester the gland appeared as incomplete tubuloacinar with only acini. These cells were characterized by spherical or sometimes oval nuclei near the base or centrally located. The gland was covered by a connective tissue capsule rich in collagenous and reticular fibers in all trimesters. The connective tissue septa divided the parenchyma into lobules. No elastic fibres were observed except around the walls of the blood vessels. The ducts and islets of Langerhans were not observed in the first trimester. However, they were clearly distinguished in the second and third trimester. The duct system consisted of intralobular ducts which were lined by low cuboidal cells in the second and third trimesters. The interlobular ducts located between the lobules in the connective tissue septa, were lined by stratified cuboidal cells in the second trimester, however, they were lined by columnar epithelium in the third trimester. The islets of Langerhans first appeared at the second trimester as pale areas among the secretory units. These structures were containing cells with rounded, oval or irregular nuclei. Morphometric study was carried out using the points-counting technique. The volume of the pancreas was determined by the water displacement method. The mean absolute volumes of the pancreas were 1.66 cm3 , 2.7cm3 and 4.18cm3 in the first, second and third trimester respectively. The first trimester revealed that the acini occupied about 44.63% (0.74 cm3), the connective tissue occupied about 38.82% (0.64cm3). The blood vessels were about 16.55% (0.28cm3). The total volume of the pancreatic components in the second trimester were as follows; the acini accounted for about 54.98% (1.48cm3), islets of Langerhans about 1.82% (0.05cm3), ducts about 3.30%(0.10cm3), connective tissue about 27.70%, (0.75cm3) and blood vessels about 12.20%(0.32 cm3). In the third trimester the acini accounted for about 60.95% (2.55 cm3), islets of Langerhans about 2.52% (0.11cm3), ducts about 2.44% (0.10cm3), connective tissue about 26.75% (1.12cm3) and blood vessels about 7.34% (0.30cm3).