Anatomy and Cell Biology 3309 Lecture Notes - Lecture 24: Common Hepatic Duct, Common Bile Duct, Cystic Duct
2 May 2018
School
Department
Professor
Histology Lecture 7 – Semester 2
Pancreas and Gall Bladder
- Bile delivered into the small intestine (duodenum)
o Together, with the enzymes produced by the pancreas (exocrine and endocrine portion)
Learning Objectives
- Describe the histology and the function of the gall bladder
- State the function of the exocrine pancreas
- Describe the structure of the pancreatic acinus
- List some digestive enzymes produced by the pancreas
- Name two duodenal hormones and explain how they control pancreatic activity
- Describe the location and function of enterokinases
Gall bladder
- Hollow organ
o Fundus, body, neck, continues into cystic duct
- Gall bladder is out growth or extension of the bile duct, which is divided into two parts
o From the liver, bile is being collected in the common hepatic duct – then it flows towards the
duodenum
▪ Common hepatic duct changes its name because there is a diversion taking place, where
the bile is sent to the gall bladder through the cystic duct and stored + concentrated in
the gall bladder merges with the
▪ Being delivered back to the cystic duct, back into the common hepatic duct, which
changes into the common bile duct
▪ Bile reaches the duodenum at the hepatopancreatic ampulla
• Name: comes from the fact that this duct merges with the pancreatic duct that
delivers digestive enzyme into the duodenum
• Both bile and digestive enzymes are delivered to the same place
- Ampulla or opening of the duct = ampulla of Vater
- Pancreas produces digestive enzymes AND produces bicarbonate rich fluid (to provide buffering so
enzymatic digestive in the duodenum happens at an appropriate pH)
- Function: concentration + storage of bile by pumping NaCl from lumen across epithelium (water follows)
find more resources at oneclass.com
find more resources at oneclass.com
- Bile flow from the hepatocytes (Bile producing cells)
o Goes through these spaces that represent the apical ends of the hepatocytes = bile canaliculi
▪ THEY ARE NOT LINED BY THEIR OWN SET OF CELLS!
▪ They are just formed by the apical side of the hepatocyte
- Toward the periphery of the lobule, some of the cells surrounding the bile canaliculi differentiate into
duct cells
o These channels = bile ductules
▪ Collect the bile toward the periphery where it gathers more CT surrounding it, into the
bile duct (part of the portal triad)
- Bile collecting into larger structures – right and left hepatic duct
- Bile flows toward the duodenum
- KNOW THAT: gall bladder is part of the bile duct passage way
find more resources at oneclass.com
find more resources at oneclass.com
Gall Bladder
- Stores and concentrates bile between meals
- Take a histological section through the gall bladder @ low magnification
o Epithelium (is prominent) = simple columnar
▪ Very tall
▪ Sits over highly vascularized lamina propia (loose CT)
▪ Find a lot of capillaries right under the epithelium
- Epithelium sits on the mucosa (lamina propia + epithelium)
- In the gall bladders, the mucosa forms branching folds sticking into the lumen
o Folds NOT finger like projections
- How do you know they are folds and not finger like projections (cut longitudinally)?
o We do NOT see any islands floating in most cases
- Underneath the mucosa there is a smooth muscle coat that blends into the submucosa
o Not really a submucosa, it is just a muscular bed
o Smooth muscle is important in delivering the bile back out into the common bile duct after it has
been stored and concentrated
- Wall consists of:
o Mucosa (simple columnar epithelium with microvilli) into folds
o Lamina propia
o Folds of surface epithelium
o Fibromuscular layer
o Serosa
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Bile delivered into the small intestine (duodenum: together, with the enzymes produced by the pancreas (exocrine and endocrine portion) Describe the histology and the function of the gall bladder. Describe the structure of the pancreatic acinus. List some digestive enzymes produced by the pancreas. Name two duodenal hormones and explain how they control pancreatic activity. Describe the location and function of enterokinases. Hollow organ: fundus, body, neck, continues into cystic duct. Ampulla or opening of the duct = ampulla of vater. Pancreas produces digestive enzymes and produces bicarbonate rich fluid (to provide buffering so enzymatic digestive in the duodenum happens at an appropriate ph) Function: concentration + storage of bile by pumping nacl from lumen across epithelium (water follows) Bile collecting into larger structures right and left hepatic duct. Know that: gall bladder is part of the bile duct passage way.
