Liver, gall bladder, biliary tree and pancreas Flashcards
What is the largest gland in the human body?
The liver
What areas does the liver occupy?
- Lies across upper abdomen under the diaphragm; in the right hypochondrium and most of epigastric region
- Surrounded by peritoneum except the bare area (related to diaphragm posteriorly)
- Should not be palpable below costal margin at mid-clavic plane
- Descends with inspiration
Where does the liver develop?
- Ventral mesentary
- Anterior to stomach / gut tube
What is the smallest functional unit of the liver?
Hepatic lobule
What do sinusoids lie between?
Sheets of hepatocytes
What do hepatocytes do?
- Produce bile
- Detoxify blood
What are the 2 surfaces of the liver?
- Diaphragmatic (bare area on this surface)
- Visceral (related to organs)
What are the 4 lobes of the liver?
- Left
- Right
- Caudate (belong to left)
- Quadrate (belong to left)
How are the caudate and quadrate lobes deemed distinct?
Functional / vascular distribution point of view
What structures lie on the visceral side of the liver?
- Stomach
- Duodenum
- Kidney
- Colon
What ligament seperates the left from the right lobes anteriorly?
Falciform ligament
What seperates the left lobe from right functionally?
- Line from vena cava to gall bladder
What is the falciform ligament a remnant of?
Ventral mesentary
What lies in the free border of the falciform ligament?
Ligamentum teres
What are the 2 peritoneal layers continous with?
- Coronary (ant + post)
- Triangular ligaments (L + R) on the undersurface of the diaphragm
What does the falciform ligament anchor the liver to?
Anterior abdominal wall
What part of the liver does the peritoneum cover?
The anterior aspect of the diaphragmatic surface
What is the lesser omentum a remnant of?
The ventral mesentary
What is the ligamentum teres (round ligament of liver) a remnant of?
The obliterated umbilical vein
What does the falciform ligament divide into?
Coronary ligaments which then form triangular ligaments
What is the ligamentum venosum a remnant of?
The ductus venosus
How many segements are there in the liver?
- 8 (4 on each lobe)
- ## Caudate and quadrate considered Left
What makes each segemnt distinct?
- Own vascular (hepatic artery and portal vein) inflow
- Vascular outflow (hepatic vein)
- Biliary drainage - Each segment can be surgically removed
What is the hepatic artery proper a branch of?
Coeliac trunk
What does the hepatic artery proper divide into?
Right and left hepatic arteries that enter the porta hepatis
What does the portal vein divide into?
Right and left branches that enter the porta hepatis behind the arteries
Where do the hepatic veins (3 or more) wmerge from and where do they drain?
- Emerge from posterior surface of the liver and drain into the inferior vena cava
What does porta hepatis mean?
The gate of the liver
How much lymph does the liver produce?
~ 33 - 50 %
How is the lymph spread from the liver?
LEave the liver and enter several lymph nodes in the porta hepatis. The efferent vessels pass to the hepatic -> coeliac nodes
Where can lymph from the bare area go to?
The diaphragm and follow the drainage from the diaphragm
Cancer can spread this way into the thrax
How can retrograde tumour spread cause jaundice?
Retrograde spread srom coeliac nodes may involve the hepatic nodes in the porta hepatis and obstruct the bile ducts causing jaundice
What is the sympathetic supply of the liver?
- Coeliac plexus (from foregut therefore greater splanchnic nerve, T5-9)
What is the parasympathetic nerve supply to the liver?
Anterior vagal trunk gives rise to a large parasympathetic hepatic branch that passes directly to the liver
What is the gallbladder?
- Muscular sac in a shallow depression on the visceral surface of the right lobe of the liver
- Stores and concentrates bile produced by the liver
What are the 3 parts of the gall bladder?
Fundus, body and neck
Where is the fundus of the gallbladder located?
- Murphy’s point
- Right mid-clavic line crosses costal margin
- Tip of right 9th costal cartilage
- Linea semilunaris crosses the right costal margin
What does a positive murphy’s sign indicate?
Acute cholecystitis (5F/6F disease)
What is the blood supply of the gall bladder?
- Cystic artery (branch of right hepatic artery) (high variation)
What is the venous drainage of the gall bladder?
Cystic vein which drains directly into portal vein
What is the lymph drainage of the gallbladder?
- Cystic lymph node situated near the gallbladder neck
- Lymph passes to the hepatic nodes along the course of the hepatic artery proper and then into coeliac nodes
What is the nerve supply of the gallbladder?
- Sympathetic (T5-9) G splanchnic
- Parasympathetic vagal fibres from the coeliac plexus
How long is the cystic duct?
~4cm long
What are the spiral folds in the neck of gallbladder and cystic duct called?
Spiral valves (of Heister)
What is the common bile duct (ductus choledochus) formed from?
Cystic duct and common hepatic duct (which is itself derived from the right and left hepatic ducts)
What does the common bile duct run in?
Hepatoduodenal ligament (portal triad)
How large is the common bile duct in diameter?
4-6 mm
What does the common bile duct join with?
Main pancreatic duct at the hepatopancreatic ampulla (of Vater) before entering into the 2nd (descending) part of the duodenum at major duodenal papilla
Where is the Sphincter of Oddi located?
Around the final part of the common bile duct
Where is the major duodenal papilla?
2nd part of duodenum
Where is pain from the gallbladder referred to?
- Epigastrum (T7-9)
- If adjacent peritoneum is involved, pain may be referred to the right shoulder by the phrenic nerve (C3, 4, 5, supraclavicular nevre)
Where does the pancreas lie in relation to the peritoneum?
- Secondarily retroperitoneal (except its tail)
Where does the pancreas lie in relation to other organs?
- Lies across the epigastrum close to major vessels
- Extends from the duodenum to the hilum of the spleen
Name the areas of the pancreas
- Head, neck, body, tail and uncinate process
- Head lies in duodenal arch
- Uncinate process extends posterior to the superior mesenteric vessels
What can carcinoma of the head of pancreas obstruct?
Common bile duct (causing painless jaundice)
Where does the main pancreatic duct begin?
Tail of pancreas
Where does the main pancreatic duct join the common bile duct?
Hepatopancreatic ampulla (of Vater)
Where does it open into the duodenum?
Major duodenal papilla
How many components does the Sphincter of Oddi have around the ducts and what are they called?
3
- Bile duct and sphincter
- Hepatopancreatic ampulla and sphincter
- Main pancreatic duct and sphincter
What are the 2 major souces of arterial blood to the pancreas?
- Coeliac runk
- Superior mesenteric artery
How does blood from the coeliac trunk reach the pancreas?
- Coeliac trunk ->
- Splenic artery ->
- Dorsal and greater pancreatic arteries
- Coeliac trunk ->
- Common hepatic artery ->
- Gastroduodenal artery ->
- Superior pancreatico-duodenal aa
What artery derived from the superior mesenteric artery supplies blood to the pancreas?
Inferior pancreatico-duodenal aa.
What part of the pancreas contains a rich anastomosis?
Head
What do the veins of the pancreas eventually drain into?
Hepatic portal vein
Describe the lymph drainage of the pancreas
- Lymph nodes are situated along the arteries that supply the pancreas
- Efferent lymph vessels drain into the coeliac and superior mesenteric lymph nodes
What is the nerve supply of the pancreas?
- Sympathetics come from T7-9 along the arteries
- Parasympathetics from vagus
Where is the trans-pyloric plane located?
- Midway between the suprasternal/jugular notch and the superior border of the pubic symphysis
- Corresponds to a plane that is midway between the xiphisternal joint and the umbilicus
- Intersects with the L1 vertebra and the costal margin of the 9th CC
What structures lie at the trans-pyloric plane?
- Fundus of gallbladder
- Pylorus of stomach
- Neck of pancreas
- 1st superior part of duodenum
- Hilum of kidney (right lower than left)
- Duodenojejunal flexure
- Termination of spinal cord at L1/2
- Origin of superior mesenteric artery
- Formation of portal vein