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Biliary and Pancreatic Anatomy. Liver. Gallbladder. Common bile duct. Pancreas. Pancreatic duct. Duodenum. Pancreatic Anatomy. Insulin and glucagon. Blood. Islet cell secreting hormones. Cells secreting pancretic juice. Duodenum. Pancreas. Pancretic duct. Common bile duct.
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Biliary and Pancreatic Anatomy Liver Gallbladder Common bile duct Pancreas Pancreaticduct Duodenum
Pancreatic Anatomy Insulin and glucagon Blood Islet cell secreting hormones Cells secreting pancretic juice Duodenum Pancreas Pancretic duct Common bile duct
Pancreatic Secretions Cell Type Component Function: • Acinar Enzymes Digestion • Ductal HCO3 and Water Protection Digestion
PANCREATIC ACINAR CELL ATP Secretin Adenyl cyclase cAMP ? Enzymes ? Ca2+ Ach Ca2+ stores IP3 CCK Primary Stimulus The Hormones also Modulate Enzyme Expression
Pancreatic Duct Cell Ca2+ CCK
Regulators of Pancreatic Secretion Cell Type PrimaryActivator Potentiator • Acinar CCK / Ach Secretin • Ductal Secretin CCK / Ach (Ca2+ ) (cAMP) Cephalic and Gastric: Neural – Ach Intestinal : Hormonal
Liver Hepatic Ducts Left Right Pancreatic Duct Common Bile Duct Cystic Duct Ampulla of Vater Gallbladder Sphincter of Oddi Duodenal Lumen
Excretory Component - Bilirubin, Drug Metabolites. Secretory Component Bile: Produced and Filtered by Hepatocytes Primary Bile Acids: Cholic Acid, Chenodeoxycholic Acid Secondary Bile Acids - Formed by Bacteria in the Intestine : Deoxycholic Acid, Lithocholic Acid
Bile Acids Secondary bile acids Primary bile acids 20% 80% Fraction of Total Deoxycholic acid Cholic acid Cholesterol Cholesterol 7-hydroxylase Amphipathic Carboxylic Acids Lithocholic acid Chenodeoxycholic acid Liver Intestine
Have both Hydrophilic and Hydrophobic domains Bile Acids are Amphipathic Formation of Micelles Co-Lipase C
Hepatic cell plate Bile canaliculus Central vein Kupffer cell Venous sinusoid Terminal bile duct Portal venule
To Systemic Circulation Rates: ml/min Aorta LIVER HEPATIC Celiac (700) (200) STOMACH SPLEEN Superior Mesenteric (700) (1800) mls/min Portal Vein PANCREAS SMALL INTESTINE Inferior Mesenteric (400) COLON
Liver Cholesterol 7-hydroxylase Cholesterol Newly synthesized bile acids (0.6 g/24 h) Bile ducts Portal vein 2 - 4 g bile-acid pool : circulated 6 - 10 times in 24 h Excreted bile acids (0.6 g/24 h) Colon Stomach Small intestine EnterohepaticCirculation
SECRETIONS of the INTESTINES Information pertaining to the next 3 slides is found in the Lecture Notes for the last Lecture
Cell Loss Blood vessels Lymph vessels Nerves Smooth muscle Connective tissue lymphocytes Plasma cells Eosinophiles Absorp- tive cells Villous epithelium Goblet cells Crypt lumen Undifferentiated Crypt epithelium Goblet Mitoses Endocrine cells Endocrine cells Muscularis mucosa
Secretions of the Small Intestine (2000 ml/day) Crypts of Lieberkuhn: Small and Large Intestine Contain Primarily Epithelial Cells, Mucus Goblet Cells, and Endocrine Cells. Water Secretion - VIP Activates Water Secretion by Elevating cAMP and Cl- conductance. Cell Growth and Differentiation: Cell Turnover at the Tip of a Villus is High (3-6 day Cycle).
Crypt Secretion Cl- Na+ cAMP Cl- PDte ? Ca2+ 3 Na+ ADP + Pi ATP K+ Na+ 2 K+ 2 Cl- H2O Key Players: cAMP Activated Cl- Channel Na+ / K+ / Cl- Co-transport Na-K ATPase VIP – neurotransmitter Histamine also can activate