Lec 7 Anatomy of the biliary tract Flashcards
Where does the right hepatic duct receive bile from?
Sectoral ducts of right liver lobe
Where does the left hepatic duct receive bile from?
Segmental ducts of left liver
What two ducts join to form the common hepatic duct?
Left and right hepatic ducts
What two ducts join to form the common bile duct?
Cystic duct and common hepatic duct
What two ducts join to form the hepatopancreatic ampulla of vater?
common bile duct and pancreatic duct
Where does the intrahepatic bile duct run parallel to?
It runs parallel to portal vein and hepatic artery
Describe smaller intrahepatic bile ducts
Much thinner wall and cuboidal epithelium
Describe larger intrahepatic bile ducts
Larger bile ducts have a loose connective tissue(flexible) and a single layer of columnar epithelium
Describe the extrahepatic bile duct
7 cms and runs in free edge lesser omentum
What does the extrahepatic bile duct join with?
Joined by cystic duct near porta hepatis
Meets with right end of pancreatic duct - ampulla vater
Enters 2nd part of duodenum at sphincter of oddi
Describe the duct wall and lumen of the extrahepatic bile duct
Duct wall - dense fibrous connective tissue
Duct wall also contains smooth muscle cells
Lumen - highly columnar epithelium
Blood - cystic vessels(from coeliac and into portal)
Location of the gall bladder
Lodged in a fossa on the visceral surface, right lobe of liver between inferior border of liver(ant) and duodenum(post)
Physical appearance of the gall bladder
Conical, pear shaped
About 10 cm in length and 3 in diameter
What is the gall bladder held by?
Held by peritoneum(forms outer wall)
What is the gall bladder divided into
fundus(lower aspect), body, neck
What does the wall of the gall bladder consist off
Simple columnar epithelium, smooth muscle
What are the functions of the gall bladder?
Concentrate and store bile
Selectively absorb bile salts
Excrete cholesterol
Excrete mucous
What is the mechanism that leads to emulsification of fat
Contraction/emptying of stomach –> fatty foods in duodenum –> cholecystokinin release –> sphincter of oddi relaxed –> emulsification of fat
How do gall stones form?
physical changes in bile (eg low bile salts and excessive cholesterol)
What is biliary colic
crampy right upper abdominal pain that comes and goes repeatedly
What is acute cholecystitis
inflammation of gall bladder that also causes pain on right upper quadrant
How is visceral pain detected?
Abdominopelvic splanchnic nerves contain this 2-way(afferent and efferent) nerve transmission from viscera within the abdominal cavity
Pain sensation from ‘foregut’ organs, so including gallbladder, pass via the coeliac ganglion
Physical appearance of pancreas
Oblong in shape(comma shaped)
12-15 cm long and 3 in width
What is the pancreas divided into?
Divided into (broad) head, (tapering) body and (sharp) tail
What is the location of pancreas?
- Head at the level of the descending duodenum
- Body behind stomach and extends towards spleen
What collects the exocrine secretions of the pancreas
Small ducts
What do small ducts unite to form?
The pancreatic duct(wirsung)
What does the duct of wirsung form when it joins with the common bile duct?
Hepatopancreatic ampulla(of vater)
Where does the ampulla of vater enter the duodenum?
Ampulla of vater enters duodenum about 10 cm post-pyloric sphincter - major duodenal papilla
Where does the secondary duct(of santorini) enter?
Secondary duct(of santorini) enters duodenum about 2 cm superior to major duodenal papilla
Arterial supply of pancreas
Pancreatic, branches from the coeliac(eg splenic) which join to form an arc(gastroduodenal + pancreaticoduodenal)
Veins of pancreas
Portal(originally from splenic + sup mesenteric)
Innervation of the pancreas
Coeliac ganglia and vagus
What type of gland is pancreas?
Both an exocrine and endocrine gland
What constitutes the exocrine portion of the pancreas
cluster AKA acini cells - pyramidal epithelium(98-99%)
What does the exocrine portion of the pancreas secrete?
Digestive enzymes, the pancreatic juice
What constitutes the endocrine portion of the pancreas?
Centroacinar cells aka islets of langerhans - cuboidal epithelium (1-2%)
What does the endocrine portion of the pancreas secrete
Secretion of hormones eg insulin
What are the causes of pancreatitis(inflammation)
Gallstones, heavy alcohol intake, cystic fibrosis and high levels of calcium or blood fats
What are the causes of pancreatic cancer?
Obstructive jaundice(gallstones) , heavy alcohol intake, smoking and genetics
location of stomach with regards to pancreas
Separated from the pancreas by the lesser sac, the stomach and pylorus lie anterior and to the pancreas
What system is the spleen a part of?
Part of the lymphatic system and is the largest single mass of lymphoid tissue
What type of gland is the spleen?
Regarded as a blood gland(not excretory nor ducts)
location of the spleen
underlies 9th, 10th, 11th rib on LHS.
At the left hypochondriac region of the abdomen
Shape of spleen
oval in shape
Physical appearance of spleen
12 cm in length but can vary - age, disease, etc
outer surface shows identations, caused by neighbouring organs(stomach, left kidney and left flexure of colon)
What does the parenchyma(inner part of spleen) contain?
Lymphatic tissue and blood vessels
nerve supply of the spleen
branches of celiac nerve plexus
Parts of the spleen parenchyma
CT capsule –> red pulp –> white pulp –> hilum
Constituents of the red pulp in spleen
blood-filled venous sinuses
Constituents of white pulp in spleen
Lymphatic tissue(lymphocytes, macrophages)
Functions of spleen
Immune(like in lymph nodes)
Removal by macrophages of old blood cells
Storage of platelets
Production of blood cells(fetal life)
