Describe the innervation of parietal peritoneum
Somatic innervation of the abdominal wall it lines, thoracic and lumbar spinal nerves
Well localised
Pain, pressure, temperature and laceration
Describe the innervation of visceral peritoneum
Poorly localised, pain referred to dermatomes
Travels with vagus nerve
Stretch and chemical irritation
Burning and cutting would cause pain in which layers of peritoneum?
Burning- both
Cutting- just parietal
What is the mesentery?
Double layers of peritoneum attaching the small intestine to the posterior abdominal wall
What is the mesocolon? What happens at the transverse colon?
Double layer of peritoneum attaching large intestine (colon) to the posterior abdominal wall
The transverse mesocolon and the greater omentum adhere together
Where is the attachement of the sigmoid mesocolon found?
At the bifurcation of the L common iliac artery
Describe the lesser omentum
Peritoneal fold between visceral surface of liver and lesser curvature of the stomach, derived from ventral mesogastrium
Encloses structures en-route to the liver (biliary ducts, hepatic artery and hepatic portal vein)
From what embryological structure is the ventral mesogastrium derived
Septum transversum (cranial mesenchyme)
What is the lesser sac?
Pouch of the peritoneal cavity loacted posterior to the liver, lesser omentum and stomach but anterior to structures located on the posterior abdominal wall
What is the gap where the lesser sac communicates with the greater sac called?
Aditus to the lesser sac
or epiploic foramen
Describe the boundaries of the lesser sac
Superiorly- diaphragm
Anteriorly- liver& lesser omentum
Posteriorly- post. abdominal wall, tranverse mesocolon
Left- L margin of greater omentum, splenorenal and gastrosplenic ligaments
What is the function of the pancreas?
Produces exocrine secretions-> digestion
endocrine secretions-> carbohydrate metabolism
Name the parts of the pancreas
head, uncinate process, neck, body and tail
Where does the head of the pancreas lie?
In the C shape of the duodenum
What lies behind the head of the pancreas?
IVC, renal veins and bile duct
Where is the uncinate process of the pancreas?
Projects from the lower part of the head to the left and posterior to superior mesenteric vessels
Where is the neck of the pancreas found?
Anterior to the superior mesenteric vein and hepatic portal vein.
What is the body of the pancreas in contact with?
Aorta (between celiac and sup. mes. a.)
the adrenal gland and the L kidney
Describe where the splenic vein and artery lies in relation to the pancreas
Splenic artery lies along the superior border of the pancreas
Splenic vein lies posterior to the body of the pancreas (sometimes embedded)
What is found anterior to the pancreas?
Stomach, peritoneum, transverse mesocolon
What is found in the splenorenal ligament?
The tail of the pancreas and the splenic artery
What is the hepatopancreatic ampulla?
Where the main pancreatic duct joins the bile duct, there is a sphincter there.
Why can pancreatitis cause jaundice?
Bile duct runs through pancreas so inflammation of pancreas can obstruct bile flow into duodenum
Describe the blood supply of the pancreas
Splenic artery, gastroduodenal and superior and inferior pancreaticoduodenal arteries
Describe the venous drainage of the pancreas
Via the superior mesenteric vein, splenic vein and into hepatic portal vein
Where does most of the lymph from the pancreas drain?
To pancreaticosplenic nodes
What level is the neck of the pancreas found?
L1-> transpyloric plane
How are the physiological lobes of the liver defined? Significance?
By a plane running between the gall bladder bed and the inferior vena cava
Shows whether that part of liver is supplied by R or L heptic artery and hepatic portal vein and whether it is drained by R or L hepatic duct
Where is bile formed and stored? (describe the route)
Bile is formed in the liver and collects in the bile canalculi, ultimately leading tot the L or R hepatic duct->common hepatic duct-> cycstic duct-> gall bladder for storage
How does bile leave the gall bladder?
Walls of the gall bladder contract, bile moves along cystic duct to the common bile duct-> major duodenal papilla-> duodenum
What happens to bile when it is being stored in the gall bladder?
It is concentrated by removal of water and some electrolytes
What forms the common bile duct?
The cystic duct + common hepatic duct
What colour is the bile duct in specimens? Why?
Green due to leakage of bile
Where is the gall bladder found?
Beneath the inferior margin of the liver, beneath the R 9th costal cartilage
Where is the bile duct found?
Upper part in the lesser omentum with the hepatic artery and the hepatic portal vein
Lower part next to hepatic portal vein and gastroduodenal artery as they pass posterior to the 1st part of the duodenum
Then passes within pancreatic tissue-> major duodenal ampulla
How may the biliary system be imaged?
By ingestion of iodine, absorbed by the small intestine and carried to the liver. Concentrated in gall bladder
Describe the blood supply and drainage of the gall bladder
Cystic artery (from hepatic artery) Venous drainage by hepatic portal vein
What is Murphy’s sign?
Breathe out then place hand over gall bladder. On inspiration the patient winces and stops inspiring
Describe the pain from gall stones
Poorly localised, travels with sympathetic fibres
Epigastrium, R hypochondrium, near R scapula
Pain worse after eating a fatty meal (fat stimulates bile production, increased obstructive pain)
What is the consequence of a large bile stone obstructing the bile duct
Not enough bile in duodenum, fat can’t be properly digested, diarrhoea and pale poo