Anatomy of the biliary tract, gallbladder, pancreas and spleen

Question 1

Where is bile secreted from?

Answer 1

Secreted by hepatocytes into bile canaliculi

Question 2

Describe the course bile travels through the biliary tree

Answer 2

Sectoral ducts of the right and left liver
Right and left hepatic ducts
Common hepatic duct
Common bile duct
Duodenum

Question 3

Describe the intrahepatic bile duct location and structure

Answer 3

Runs parallel to portal vein and hepatic artery
Smaller bile ducts (ductules) – much thinner wall and cuboidal epithelium
Larger bile ducts have a loose connective tissue (flexible) and single layer of columnar epithelium

Question 4

Where is the extrahepatic duct?

Answer 4

Runs in the free edge of the lesser omentum

Question 5

Describe the structure of the extrahepatic duct

Answer 5

Joined by cystic duct near porta hepatis
Meets with right end of pancreatic duct – ampulla Vater
Enters 2nd part duodenum at sphincter of Oddi

Question 6

Describe the basic histology of the extrahepatic duct

Answer 6

Duct wall – dense fibrous connective tissue and smooth muscle cells
Lumen – highly columnar epithelium
Blood supply - cystic vessels (from Coeliac and into Portal)

Question 7

Give the location of the gallbladder

Answer 7

Lodged in a fossa on the visceral surface, right lobe of liver
Between inferior border of liver (ant) and duodenum (post)
Held by peritoneum

Question 8

What is the gallbladder divided into?

Answer 8

Divided into fundus (lower aspect), body, neck

Question 9

What is the wall of the gallbladder composed of?

Answer 9

Simple columnar epithelium, smooth muscle

Question 10

List the main functions of the gallbladder

Answer 10

Concentrate and store bile
Selectively absorb bile salts
Excrete cholesterol
Excrete mucous

Question 11

Describe the mechanism by which bile secretion is stimulated to occur

Answer 11

Contraction /emptying of stomach

Fatty foods in duodenum

Cholecystokinin release

Sphincter of Oddi relaxed

Emulsification of fat

Question 12

What causes the sphincter of oddi to relax?

Answer 12

Cholecystokinin

Question 13

Describe gallstones

Answer 13

Physical changes in bile, e.g.
low bile salts
excessive cholesterol

Stones can partially or fully obstruct flow of bile

Question 14

Describe biliary colic

Answer 14

Crampy right upper abdominal pain that comes and goes repeatedly

Question 15

Describe acute cholecystitis

Answer 15

Inflammation gallbladder that also causes pain on right upper quadrant

Question 16

How is visceral pain carried from organs within the abdomen?

Answer 16

Alongside sympathetic neurons

Question 17

Pain sensation from ‘foregut’ organs, so including gallbladder, pass via the …

Answer 17

Coeliac ganglion

Question 18

What is the pancreas divided into?

Answer 18

Divided into (broad) head, (tapering) body and (sharp) tail

Question 19

Describe the location of the pacreas

Answer 19

Head at the level of the descending duodenum
Body behind stomach and extends towards spleen
Just below L1 at the transpyloric plane

Question 20

Where are pancreas exocrine secretions collected?

Answer 20

Into small ducts

Question 21

What do the small ducts of the pancreas unite to form?

Answer 21

Pancreatic duct (Wirsung)

Question 22

What forms when the pancreatic duct and common bile duct join?

Answer 22

Hepatopancreatic ampulla (of Vater)

Question 23

Describe where the ampulla of vater enters the duodenum

Answer 23

Ampulla of Vater enters duodenum about 10 cm post-pyloric sphincter – major duodenal papilla

Question 24

Describe where the secondary duct of santorini enters the duodenum?

Answer 24

Secondary duct (of Santorini) enters duodenum about 2 cm superior to major duodenal papilla

Question 25

List the veins, arteries and nerves supplying the pancreas

Answer 25

- Arteries: pancreatic, branches from the Coeliac (e.g. splenic) These join forming an arc (gastroduodenal + pancreaticoduodenal) - Veins: Portal (originally from splenic + sup mesenteric) - Nerves: Coeliac ganglia and Vagus

Question 26

Is the pancreas an exocrine or endocrine organ?

Answer 26

Both

Question 27

Describe the cells and function of the exocrine portion

Answer 27

Cluster aka acini cells – pyramidal epithelium (98-99%) | Secretion of digestive enzymes, the pancreatic juice

Question 28

Describe the cells and function of the endocrine portion

Answer 28

centroacinar cells aka islets of Langerhans – cuboidal epithelium (1-2%) secretion of hormones, e.g. insulin

Question 29

List some causes of inflammation of the pancreas

Answer 29

gallstones heavy alcohol intake cystic fibrosis high levels of calcium or blood fats

Question 30

List some causes of pancreatic cancer

Answer 30

obstructive jaundice (gallstones) heavy alcohol intake smoking genetics

Question 31

Describe the spleen

Answer 31

Largest single mass of lymphoid tissue Regarded as a blood gland (not excretory nor ducts) Oval in shape

Question 32

Give the location of the spleen

Answer 32

Underlies 9th 10th 11th rib on LHS | At the left hypocondriac region of the abdomen

Question 33

Describe the outer surface of the spleen

Answer 33

Outer surface shows indentations, caused by neighbouring organs (stomach, left kidney and left flexure of colon)

Question 34

What is contained in the parenchyma (inner part) of the spleen?

Answer 34

Parenchyma (inner part of spleen): contain the lymphatic tissue and blood vessels

Question 35

State the innervation of the spleen

Answer 35

Braches of celiac nerve plexus

Question 36

Describe the parenchyma of the spleen

Answer 36

Red pulp: blood-filled venous sinuses | White pulp: lymphatic tissue (lymphocytes, macrophages)

Question 37

What is the function of the spleen

Answer 37

Immune (like in lymph nodes) Removal of old blood cells by macrophages Storage of platelets Production blood cells (fetal life)