Abdominal Viscera: Liver, pancreas and spleen Flashcards
Where does the liver develop embryologically? What is it derived from?
Develops in the ventral mesentery of the foregut.
Foregut derived
What is the spleen derived from embryologically?
Mesoderm
What does the ventral mesentery contain during embryological development?
Liver
Gallbladder
Part of pancreas
What does the dorsal mesentery contain during embryological development?
Part of pancreas
Spleen
During embryological development, what does the falciform ligament contain?
Umbilical vein
What is the lesser sac? What are its borders?
Area of peritoneal cavity behind the stomach
Anterior: stomach and lesser omentum
Posterior: Peritoneum (behind are pancreas, left kidney and adrenal gland)
Superior: Liver
Inferior: Greater omentum
What is the epiploic foramen?
The hole in the peritoneum providing the only access to the lesser sac in an adult.
What is the greater sac?
Everything in the peritoneal cavity apart from the lesser sac.
Consists of supracolic and infracolic compartments
What are the supracolic and infracolic compartments?
Supracolic: region of the greater sac that is superior to the transverse colon and anterior to greater omentum.
Infracolic: region of the greater sac that is inferior to the transverse colon and posterior to greater omentum.
What are the surface anatomy markings of the liver
Inferior border: costal margin (may be palpable in epigastric region)
Superior border: diaphragm, roughly 5th rib in mid-clavicular line
What holds the liver in position against the diaphragm?
Peritoneum, except in an area where the liver has grown out of the ventral mesentery= bare area (no peritoneal covering)
What is the falciform ligament? Where is it?
Remnant of the umbilical vein, sits within the falciform ligament of the liver.
What are the 4 anatomical lobes of the liver?
Right, left, caudate, quadrate
What does the cystic artery supply? What does it come off?
Supplies gall bladder
Comes off right hepatic artery
What is the portal vein formed from? Where is it formed?
Superior mesenteric vein joining the splenic vein behind the neck of the pancreas
Where are the porto-systemic anastamoses? What is the clinical relevance of these?
Lower oesophagus
Umbilicus
Rectum
Increased portal venous pressure (e.g. in liver cirrhosis) causes dilation of anastamoses and shunt of blood from portal to systemic venous system.
Results in oesophageal varices, anorectal varices or caput medusae.
How is the pancreas formed embryologically?
Formed from 2 embryological tissue buds:
- Dorsal pancreatic bud in dorsal mesentery
- Ventral pancreatic bud in ventral mesentery
Come together during gut tube rotation
Duct systems from gall bladder and pancreas join together in this process.
Where can pain from pancreatitis refer to?
Epigastric region and back
What is the clinical relevance of the subphrenic and hepatorenal recesses?
Fluid can accumulate and cause infection leading to abscesses.
What is an annular pancreas?
During embryological formation the ventral pancreatic bud grows around the duodenum instead of behind it causing obstruction
What can cause blockage of the major duodenal papilla?
Gall stones
Tumours of pancreatic head
=jaundice as bile cannot drain, bilirubin accumulation
What is the minor duodenal papilla?
Small drainage route for the pancreas separate to the main pancreatic duct, sits proximal to the major duodenal papilla
What is the blood supply to the pancreas?
Coeliac trunk, SMA and splenic artery
What is the lymph drainage route from the spleen?
Coeliac nodes–> thoracic duct–> supraclavicular nodes
Where is the spleen located?
Posterior abdominal wall, ribs 9-11 or 10-12
How can the spleen be damaged? What else could be damaged at the same time?
Rib fractures: can also damage lungs (through costodiaphragmatic recess) and diaphragm. Blood from spleen can bleed through diaphragm into thoracic cavity.
In what region of the abdomen (surface anatomy) is the spleen located?
Left hypochondrium
What is the blood supply to the spleen?
Coeliac trunk–> splenic artery
What is the venous drainage of the spleen? What is the significance of this?
Portal venous system: vulnerable to damage in portal HTN–>splenomegaly
Where should you begin to examine for splenomegaly?
Right iliac fossa
What are the close anatomical relations of the spleen?
Stomach
Tail of pancreas
Splenic flexure of large intestine
Left kidney
