Clinical Anatomy Of The Pancreas, Liver + Spleen Flashcards
What are the liver, pancreas and spleen embryological derivatives of?
Liver + pancreas = foregut derivatives
Spleen = mesodermal derivative of mesenchymal origin (but share foregut blood supply)
What does the ventral mesentery contain? What does it form in adults?
Liver
Gallbladder
Part of pancreas
Lesser omentum
What does the dorsal mesentery contain? What does it form in adults?
Spleen
Part of pancreas
Greater omentum
What does the falciform ligament contain in embryology? What does it become in adults?
Umbilical vein; the major vein that drains blood from placenta into developing embryo
Becomes a fibrous chord called the ligamentum teres in adults
What does the stomach do in embryology?
- Rotates right by 90o about a longitudinal axis + clockwise 90o about a sagittal axis
- Liver grows out of top of ventral mesentery
- Pancreas + duodenum become 2ndarily retroperitoneal
What structure joins the lesser and greater sac?
Epiploic foramen
What are the boundaries of the lesser sac?
Transverse mesocolon inferiorly
Splenorenal + gastrophrenic ligament to the right
Left coronary ligament superiorly
Bare area of liver to the left
What can paracolic gutters help you to do?
Track the movement of fluid
What compartments exist in the abdomen? Where are they?
Supracolic: sits above transverse colon mostly & in front of greater omentum
Infracolic: sits below transverse colon mostly + behind the greater omentum
Both in greater sac
Where does the liver sit?
Mainly in R hypochondrium + extends across epigastric + L hypochondrium
Follows upper limit of diaphragm (5th rib at MCL) so is associated with costodiaphragmatic recess
Where is the liver palpable?
Margin not normally palpable below costal margin although it can be near the midline below the sternum
How should you clinically examine the liver?
Percussion
Palpation at costal margin; moves inferiorly on inspiration
What do you need to tell the patient to do when taking a liver biopsy? Why?
To take a deep breath out because the lungs will drop down over the margin of the liver when a deep breath is taken in so could be punctured
What are the 4 anatomical lobes of the liver?
Anterior:
Right
Left
Posterior:
Caudate (superior)
Quadrate (inferior)
What splits the left and right lobe of the liver?
Falciform ligament
What major vein comes into the liver?
IVC -> hepatic vein
What is the porta hepatis?
Entry/exit point for portal vein, bile duct, hepatic artery + autonomic nerves
What is the liver separated into?
8 functionally independent segments where each segment is served by its own hepatobiliary division
What are the consequences of organ segmentation?
Surgically, a segment can be removed/dead + the rest of the organ functions fine
What is the livers point of reflection?
When peritoneum is reflecting/turning back on itself + is stuck to the diaphragm meaning the liver moves with breathing
What is the bare area of the liver?
The part of the liver not covered in peritoneum, in DIRECT contact with the diaphragm bordered by the coronary + triangular ligaments
What are the liver ligaments? What are their names?
When the peritoneum lifts off the liver + is stuck to the diaphragm
Coronary
Triangular
What is the blood supply to the liver?
Portal vein (70%) Hepatic artery (30%)
Where does the hepatic artery come from and what does it run through?
Coeliac trunk
Runs in free edge of lesser omentum in hepatoduodenal ligament (contains common bile duct + portal vein too) so can be accessed via epiploic foramen
What is the blood supply to the gallbladder?
Cystic artery from right hepatic artery (normally)
What are the branches of the coeliac trunk?
Common hepatic -> gastroduodenal -> hepatic -> L + R hepatic & cystic
What is the lesser omentum?
The peritoneum between the stomach + liver
What is the pringle manoeuvre?
When you the pinch the free edge of lesser omentum through the epiploic foramen o cut off the blood supply to the liver as this contains the common bile duct, hepatic artery + portal vein
Where is the portal vein formed and what forms it?
Formed posterior to pancreatic neck
Formed from the splenic vein, SMV + IMV (joins either at splenic or onto SMV)
What organs does the portal vein drain? What consequences does this have?
Spleen + majority of GI tract drain to the liver so if there is pressure in the portal venous system, the spleen for e.g. can become enlarged
What is the porto-systemic anastomoses? What consequence may this have?
Joining of portal + systemic venous systems in the inferior oesophagus, umbilicus + rectum so increased portal venous pressure can dilate these anastomoses causing oesophageal/anorectal varices and/or caput medusae
Where can gallstones get stuck? What can they cause?
In the duct system
Pain (biliary colic), cholecystitis + jaundice
What are the different parts of the gallbladder?
Fundus (9th cc/L1 tip ~ at transpyloric plane)
Body
Neck
Drains into cystic duct (CD)
R + L hepatic duct form the common hepatic duct (CHD)
CD + CHD = bile duct
Where does the bile duct drain into?
2nd part of duodenum at major papilla (marks foregut/midgut divide) which is guarded by the hepato-pancreatic sphincter
What are the functions of the gallbladder?
Concentrates bile
Stores bile (when sphincter Oddi is shut)
Selective absorption of salts
What valve keeps the cystic duct open?
Spiral valve (raised spiral of mucosa)
What type of imaging can be done to look for a gallstone in the duct system?
Endoscopic Retrograde Cholangio-Pancreatography (ERCP) that passes an endoscopy through the major duodenal papilla
How is the gallbladder examined?
Dr puts pressure under right costal margin at 9th cc level + asks the patient to inhale - inspiration causes gallbladder to descend onto fingers producing pain if it is inflamed in cholecystitis (this pain = Murphy’s sign)
What peritoneal recesses exist? Why is this important clinically?
Subphrenic space
Hepato-renal space (Morrison’s pouch)
Recesses gravity dependent so can be an area that accumulates fluid, for infection spread or abscess formation from the abdomen when patient is supine
Where can gallbladder pain refer to? Why?
Epigastrium: gallbladder is a foregut structure
R hypochondrium: irritation to local tissues
R shoulder: gallbladder sits under diaphragm + irritates it (C3-5)
Where does the pancreas sit?
Epigastric region extending to the L hypochondrium sitting posterior to stomach in ‘C’ of duodenum
Neck sits on transpyloric plane (L1) whilst tail sits near splenic hilum
What is the pancreas?
Retroperitoneal foregut derivative with 4 (or 5) anatomical parts + exocrine & endocrine functions
What can be a consequence of pancreatitis?
Pain (back/epigastric region)
Fluid accumulation in lesser sac
How does the pancreas develop in embryology?
From 2 different embryological tissue buds: ventral & dorsal
Ventral bud forms the bile duct whilst the dorsal bud is the long shape of the pancreas so they must rotate around duodenum to form characteristic structure
What is an annular pancreas?
When the embryological ventral pancreas bud does not swing round the duodenum, but splits + circles the duodenum obstructing it causing vomiting + failure to thrive in newborns
What are the drainage points of the pancreas?
Minor duodenal papilla: receives accessory pancreatic duct
Major duodenal papilla: drains pancreatic + hepatic secretions
How can the major duodenal papilla become blocked? What is the consequence of this?
Stones or tumours of pancreatic head
Pancreatic/bile duct drainage is blocked which can cause jaundice as bile is accumulating
Where does the pancreas and duodenums arterial supply come from? Where is the venous supply?
Coeliac trunk (gastroduodenal, superior pancreaticoduodenal & splenic artery)
SMA (inferior pancreaticoduodenal artery)
Venous drainage into portal system tracks with arterial supply
What is the lymph drainage of the pancreas and duodenum?
Coeliac nodes (follows arterial supply) -> thoracic duct -> supraclavicular nodes
Why does the pancreas need a rich blood supply?
Because it has many roles i.e. endocrine AND exocrine
Where does the spleen sit?
Left posterolateral abdominal wall intraperitoneally in L hypochondrium under costal margin
Related to ribs 9-11 or 10-12
What injuries may damage the spleen?
Rib fracture in ~ ribs 9-12
Blood forced trauma - tissue bleeds profusely if injured & repair is difficult due to delicacy (alike liver)
What is the costodiaphragmatic recess?
An area of the thoracic cavity that the lungs can extend into during normal tidal inspiration
What other structures is the spleen in contact with?
The diaphragm at ribs 9–12 in the area of the costodiaphragmatic recess
Touches the stomach, tail of pancreas (sometimes), L kidneys + colon (splenic flexure)
What is the spleens blood supply? What is its venous drainage? What is its lymph drainage?
Coeliac trunk -> splenic artery (torturous course) -> divides into segmental branches (no anastomoses between branches so damage to any part is irreparable)
Drains into portal venous system
Lymph drains into coeliac nodes (follows arterial supply)
Can people live without a spleen?
Yes but need medical intervention
