Development of liver, pancreas & spleen - ROLL NO. 38.pptx

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1. Development of Liver, Pancreas & Spleen By - Jai Vardan Singh Billowria Roll No. – 38

2. DEVELOPMENT OF LIVER Develops from endodermal hepatic bud / hepatic diverticulum from ventral aspect at distal end of foregut, just a its junction with midgut.( 4 th week ) Hepatic bud grows into ventral mesogastrium & through it into septum transversum . Hepatic bud elongates & divides into larger cranial part − pars hepatica & smaller caudal part − pars cystica . Pars cystica forms gallbladder & cystica duct . Pars hepatica divides into left & right part (develops right & left lobes) .

3. HEPATIC ARCHITECTURE & EXTRAHEPATIC BILIARY APPARATUS FORMATION

4. ANOMALIES OF LIVER

5. ANOMALIES OF GALLBLADDER ANOMALIES OF EXTRAHEPATIC DUCT SYSTEM

6. DEVELOPMENT OF PANCREAS Appears at approximately 5 weeks of gestation as two outpouchings of the endodermal lining of the duodenum just distal to the forming stomach called dorsal & ventral buds . The ventral bud rotates toward the dorsal bud as it is “carried” by the common bile duct. The ventral and dorsal buds fuse to form one mass (8 th week). Ventral bud forms lower part of head & uncinate process . Dorsal bud forms upper part of head, neck, body & tail .

7. Ducts of buds are separate & They open separately in duodenum initially. Ducts of dorsal & ventral buds anastomose with each other. Duct of ventral bud forms proximal part of main pancreatic duct. Duct of dorsal bud forms distal part of main pancreatic duct & accessory pancreatic duct. Parenchyma develops from branching of buds into adjacent mesoderm & consist of − Exocrine part − develops from proliferation of primitive ducts . Endocrine part − develops from cells separated from duct system . DUCT SYSTEM & PARENCHYMA DEVELOPMENT

8. ANOMALIES OF PANCREAS ANNULAR PANCREAS − Pancreatic tissue surrounding duodenum completely & may obstruct it.

9. ANOMALIES OF PANCREAS

10. DEVELOPMENT OF SPLEEN Develops from mesoderm in dorsal mesogastrium .( 5 th week ) It develops as a collection of mesenchymal cells to form small lobular masses of splenic tissue called spleniculi . These lobules fuse to form single mass of spleen . Mesenchymal cells’ proliferation makes splenic mass project in left layer of dorsal mesogastrium which forms gastrosplenic & lienorenal ligament . This mass gets covered by lesser sac of peritoneum .

11. ANOMALIES OF SPLEEN