Accessory Digestive Organs

Hepatocytes

bile producing cells

Emulsification

mechanical digestion of bile breaking down fats

Pancreatic juice

mixture of water, salts, several enzymes, sodium bicarbonate

Hepatopancreatic ampullae

Pancreatic duct + common bile duct

Acini

clusters of glandular epithelial cells that secrete pancreatic juice into pancreatic ducts leading to duodenum (exocrine function), 99% of cell

Islets of Langerhans

secrete a variety of hormones including glucagon/insulin, remaining cells organization

Enzymes in pancreatic juice

Pancreatic amylase - carbs

Trypsin/chymotrypsin/carboxypeptidase/elastase - proteins

pancreatic lipase - triglycerides (lipids)

ribonuclease/deoxyribonuclease - nucleic acids

Liver

contains specialized cells called hepatocytes that produce bile

Bile

digestive agent that emulsifies fats, collected by a system of ducts that merge to form common hepatic duct

Common bile duct

Common hepatic duct (liver) + cystic duct (gallbladder) = common bile duct, empties into duodenum

Liver functions

metabolic regulation of proteins/lipids/carbs - convert them in form, make them available for various functions in the body, synthesize certain types

processing of drugs/toxins

hematological regulation

storage of specific vitamins/minerals (storage of glucose as glycogen, stores significant amount of vitamins A,D,E,K,B12)

Hematological regulation of the liver

phagocytize aged RBC and WBC

bilirubin from the heme group in RBC is absorbed from blood and added to bile

bilirubin is metabolized by bacteria in the large intestine and eliminated in feces

Gallbladder

temporarily stores bile produced by the liver

stimulated by the hormone cholecystokinin to release bile

production of CCK is triggered by fatty acids in chyme

CCK triggers release of pancreatic juice as well

Salivary Glands

Produce secretion of saliva keeping the mouth interior moist and increasing during ingestion

lubricates, dissolves and starts chemical digestion

Saliva

~1 quart produced every day

99.5% water and 0.5% solutes (mucus, amylase, salts)

Mucus

lubricates food so that it can be easily swallowed

Amylase enzyme

begins digestion of carbohydrates