PANCREAS INFO

ANATOMY

BILIARY TREE: System of vessels that direct secretions from liver, gallbladder and pancreas through a series of ducts into the duodenum

ACINAR CELLS: Cells in the pancreas that secrete digestive enzymes (exocrine secretion), located near the pancreatic duct

ISLETS OF LANGERHANS: Endocrine secretion of insulin and glucagon to regulate homeostasis of blood glucose levels, contain alpha cells (produce glucagon) and beta cells (produce insulin)

HIGH BLOOD GLUCOSE = secretion of insulin by beta cellsCells absorb more glucoseLiver converts glucose to glycogenFat cells convert glucose to fatty acidsATP synthesis increases

LOW BLOOD GLUCOSE = secretion of glucagon by alpha cellsIncreased breakdown of glycogen to glucose in liver and muscleIncreased synthesis & release of glucose in the liver

DISEASES OF THE PANCREAS

TYPE 1 DIABETES"Chronic autoimmune disease" - Eisenbarth (1986)T-cells attack insulin-secreting beta cells in pancreatic islets, causing no insulin to be produced as the cell becomes less responsiveUsually manifests in small children and is difficult to treat as need to restore beta cell levels but also to prevent reattack from T-cells

TYPE 2 DIABETESMore common type of diabetes (85-90% of all diabetes cases)Chronic, progressive disease Characterised by abnormal insulin action and secretionPredicted to be the 7th leading cause of death in 2030 (WHO)Genetics/Obesity/Ageing ---> Insulin resistanceThis leads to Beta cell compensation, Hyperinsulinaemia and normal glucose toleranceWhich leads to Impaired Beta cell functionsImpaired Beta cell function ---> impaired glucose tolerance ---> Beta cell failure ---> Type 2 diabetesInsulin resistance often occurs years before diabetes is diagnosedBeta cells = 60% of Islet endocrine cells, so Islets increase in size and number as the number of Beta cells increases (when tissue cells don't respond to insulin as sensitively as they should)In an insulin-resistant patient, Beta cells can be 90% of islet cellsIslets become overwhelmed from trying to compensate and the Beta cells dieThe amount of insulin being secreted significantly reduces and Type 2 Diabetes mellitus occurs

EMBRYONIC DEVELOPMENT

Triggered by endodermal proliferationDay 35 biliary system developed as a tubular structurePancreas buds from hepatic diverticulum (dorsal & ventral buds)Day 40 theses fuse together after ventral bud rotates clockwise around the foregutDay 45 the biliary tree has formed, linking structures together