Liver Gallbladder Common bile duct Pancreas Pancreatic duct Duodenum Biliary and Pancreatic Anatomy

Islet cell secreting hormones Cells secreting pancretic juice Insulin and glucagon Pancretic duct Duodenum Pancreas Common bile duct Blood Pancreatic Anatomy

Pancreatic Secretions Acinar Enzymes Digestion Ductal HCO 3 and Water Protection Digestion Cell Type Component Function:

ATP cAMP Adenyl cyclase ? ? Ca 2+ stores Secretin Ach CCK Enzymes IP 3 The Hormones also Modulate Enzyme Expression Primary Stimulus PANCREATIC ACINAR CELL

Ca 2+ CCK Pancreatic Duct Cell

Regulators of Pancreatic Secretion AcinarCCK / Ach Secretin Ductal Secretin CCK / Ach Cell Type PrimaryActivator Potentiator (Ca 2+ ) (cAMP ) Cephalic and Gastric: Neural – Ach Intestinal : Hormonal

Liver Hepatic Ducts Right Left Common Bile Duct Cystic Duct Gallbladder Ampulla of Vater Duodenal Lumen Pancreatic Duct Sphincter of Oddi

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 Primary bile acids Secondary bile acids Cholesterol Cholic acid Deoxycholic acid Chenodeoxycholic acid Lithocholic acid Liver Intestine Cholesterol 7-hydroxylase 80% 20% Fraction of Total Amphipathic Carboxylic Acids

C Have both Hydrophilic and Hydrophobic domains Formation of Micelles Co-Lipase Bile Acids are Amphipathic

Central vein Hepatic cell plate Bile canaliculus Venous sinusoid Terminal bile duct Kupffer cell Portal venule

Aorta (200) Celiac (700) Portal Vein Superior Mesenteric (700) Inferior Mesenteri c (400) LIVER STOMACH SPLEEN PANCREAS SMALL INTESTINE COLON To Systemic Circulation (1800) mls/min HEPATIC Rates: ml/min

Cholesterol 7-hydroxylase Newly synthesized bile acids (0.6 g/24 h) Cholesterol g bile-acid pool : circulated times in 24 h Excreted bile acids (0.6 g/24 h) Liver Bile ducts Portal vein Colon Small intestine Stomach Enterohepatic Circulation

SECRETIONS of the INTESTINES Information pertaining to the next 3 slides is found in the Lecture Notes for the last Lecture

Blood vessels Lymph vessels Nerves Smooth muscle Connective tissue lymphocytes Plasma cells Eosinophiles Villous epithelium Undifferentiated Goblet Mitoses Endocrine cells Crypt epithelium Crypt lumen Muscularis mucosa Absorp- tive cells Goblet cells Endocrine cells Cell Loss

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). Secretions of the Small Intestine (2000 ml/day)

Crypt Secretion H2OH2O 2 Cl - Na + K+K+ PDte cAMP ? Ca 2+ Cl - Na + ATP ADP + Pi 3 Na + 2 K + Key Players: cAMP Activated Cl - Channel Na + / K + / Cl - Co-transport Na-K ATPase VIP – neurotransmitter Histamine also can activate