Week 1/2 - A(2) - Anatomy 3&4 - Liver, Spleen, Gallbladder, Pancreas and Small Intestines, arterial/venous supply/biliary tree

Question 1

What are the foregut organs? What is the main artery that comes from the abdominal aorta to supply it and at what level? What does it trifurcate into?

Answer 1

Foregut organs - oeseophagus, stomach to mid duodenum (also liver, gallbladder, spleen, 1/2 of pancreas) The coeliac trunk (coeliac axis) supplies the organs of the foregut Coeliac trifurcates into the left gastric, spelnic and common hepatic artery

Question 2

Different branches arise from the trifurcation of the coeliac trunk Can you name the branches arising from these arteries? * Left gastric - branches (2) * Splenic artery - branches (2) and arteries (2) * Common hepatic artery - arteries (2) Which goes to the fundus of the stomach? Which goes to greater curvature of the stomach?

Answer 2

Left gastric - gives gastric & oeseophageal branches Splenic - gives splenic branches & pancreatic branches, short gastric arteries (fundus) left gastro-omental artery (greater curvature) Common hepatic - proper hepatic & gastroduodenal artery

Question 3

The two arteries that arise from the common hepatic artery have their own branches What are these?

Answer 3

Gastroduodenal artery - right gastro-omental artery and the superior pancreatico-duodendal artery Proper hepatic artery - right gastric, right and left hepatic artery Right hepatic artery gives the cystic artery

Question 4

How would the route of the splenic artery be described? What are the anatomical relations of the spleen? Is it intra or retroperitoneal? What ribs protect it?

Answer 4

The splenic artery has a torturous route to the spleen The spleen has Diaphragm posteriorly Stomach anteriorly Splenic flexure inferiorly Left kidney medially Spleen is protected by ribs 9-11 - fracture could pierce it

Question 5

What is the blood supply to the stomach? State which artery the branch arises from (no need to do this if arising from coeliac trunk) Which arteries anastamose?

Answer 5

Short gastric arteries (from splenic) - fundus Right gastric (from proper hepatic branch of common hepatic) and left gastric anastamose at the lesser curvature Right gastro-oemental (from gastroduodenal branch of common hepatic) and left gastro-omental (from splenic) anastamose at the greater curvature.

Question 6

What is the blood supply to the liver - state what forms these vessels? Which ribs protect the liver? What are the four anatomical segements?

Answer 6

Hepatic artery (proper hepatic giving right and left) only supplies 20-25% Hepatic portal vein (union of spelnic vein with SMV) - supplies the rest Liver protected by ribs 7-11 4 anatomical segments * Right lobe * Left lobe * Caudate lobe (superior) * Quadrate lobe (inferior)

Question 7

What are the anatomical relations of the liver? Do the hepatic veins or IVC have valves?

Answer 7

Diaphragm superiorly, anterior and posteriorly Anterior aspect of stomach medially Gallbladder posteriorly and inferiorly Hepatic flexure inferiorly Right kidney/adrenal gland, IVC and abdominal aorta posteriorly

Question 8

What does each functional segment of the liver have to allow it function? What are the two clinically important areas of the peritoneal cavity related to the liver and which is the most inferior part of the peritoneal cavity when lying flat?

Answer 8

Each functional segment has its own blood supply (hepatic artery and portal vein), venous drainage and bile drainage Hepatorenal recess (between liver and posterior abdominal wall) - lowest point when lying flat (aka Morison’s pouch)* sub-phrenic recess (between liver and diaphragm)

Question 9

Which arteries supply the foregut, midgut and hindgut? What vertebral level do the arteries arise? Which veins drain the foregut, midgut and hindgut? Where do the veins drain into?

Answer 9

Foregut - Coeliac trunk - T12. Splenic vein -> hepatic portal vein Midgut - Superior mesenteric artery- L1 Superior mesenteric vein-> hepatic portal vein Hindgut - Inferior mesenteric artery - L3. Inferior mesenteric vein -> splenic vein

Question 10

Where does the hepatic portal vein drain and for what? Where does the blood from the liver drain?

Answer 10

Hepatic portal vein drains blood from the foregut, midgut and hndgut to the liver for first pass metabolism ‘Cleaned’ blood from the liver drains into sinusoids which drain into central veins which drain into hepatic veins - hepatic veins drain into the inferior vena cava which goes back to right atrium

Question 11

What attaches the liver to the diaphragm? What attaches the liver to the anterior abdominal wall? * What lobes do the remnant of the umbilical vein and ductus venosus separate? * What are the remnants known as?

Answer 11

Coronary ligaments attach the liver to the diaphragm Falciform ligaments attach the liver to the anterior abdominal wall Ligamentum teres aka round ligament (umbilical vein remnant) separates the quadrate and left lobe Ligamentum venosum (ductus venosus remnant) separates the caudate and left lobe

Question 12

What are the two parts of the gallbladder? Which part narrows to become the cystic duct and what is this a potential site for? What is the blood supply and where is pain felt?

Answer 12

Two parts are the body and neck of the gallbladder Neck narrows to become the cystic duct - potential site for gallastone impaction Blood supply is via the cystic artery (branch of right hepatic artery) Pain is felt in the right upper quadrant - can refer to right shoulder

Question 13

Define jaundice?

Answer 13

Jaundice is a clinical sign describing yellow pigmentation of the skin, sclera, and mucous membranes due to raised plasma bilirubin, a bile pigment

Question 14

What is bilirubin? Where is bilirubin formed? What is bilirubin used to form? Where does this product then travel?

Answer 14

Bilirubin is a normal by-product of red blood cells Bilirubin is formed in the spleen as this is where the breakdown of red blood cells mainly occurs The bilirubin is then used to form bile in the liver Bile travels through the biliary tree * a set of tubes connecting the liver to the 2nd part of the duodenum

Question 15

What is the gallbladders role in bilirubin? What is bile important for? What does the pancreas also excrete into the 2nd part of the duodenum? What is this necessary for?

Answer 15

The gallbladder stores and concentrates the bile Bile is important for the normal absorption of fats from the small intestine The pancreas also excretes digestive enzymes into the 2nd part of the duodenum which is necessary for the digestion of food

Question 16

Where is the portal triad found - both names? What does it consist of?

Answer 16

Portal triad is found in the free edge of the lesser omentum aka the hapatoduodenal ligament It consists of the Proper hepatic artery Hepatic portal vein Common bile duct

Question 17

How is the common bile duct formed? What does this join with to form? Where does it drain?

Answer 17

Common bile duct is formed from the cystic duct joining with the common hepatic duct The common bile duct joins with the pancreatic duct to form the Ampulla of vater which drains through the major duodenal papilla into the 2nd half of the duodenum

Question 18

What is an anatomical sphincter? * What are the anatomical sphincters in the biliary tree? * What type of muscle are they?

Answer 18

An anatomical sphincter is a discrete area where muscle completely encircles the lumen of the tract. The three anatomical sphincters are formed from smooth muscle - Common bile duct sphincter Pancreatic duct sphincter Sphincter of oddi (at the major dudodenal papilla)

Question 19

What is the purpose of the sphincter of oddi?

Answer 19

Purpose is to control the flow of bile and pancreatic juices into the dudoenum and prevent reflux of duodenal contents into the ducts

Question 20

What does ERCP stand for? What does it do? How does it enter the biliary tree?

Answer 20

Endoscopic retrograde chlangiopancreatography Investigative and often treatment used to study the biliary tree & the pancreas Endoscope inserted though oral cavity to duodenum where a cannula is inserted into the major duodenal papilla- radio-opaque dye injected for visualization

Question 21

Name two obstructions of the biliary tree that can cause post-hepatic jaundice? How does it lead to this?

Answer 21

Post-hepatic jaundice - eg due to gallstones or carcinoma of the head of the pancreas Cause bile to flow back into the liver leading to increased bilirubin levels

Question 22

What are the 5 parts of the pancreas? What part does the duodenum form a C-shape around? What are the functions of the pancreas?

Answer 22

Pancreas - head, neck, body, tail and ucinate process The duodenum forms a C-shape around the head of the pancreas Exocrine pancreas secretes digestive enzymes into the pancreatic duct Endocrine pancreas is important in insulin + glucagon production

Question 23

Exocrine pancreas secretes digestive enzymes into the pancreatic duct - what cells secrete this? Endocrine pancreas is important in insulin + glucagon production - what cells secrete this?

Answer 23

Exocrine pancreas - It is the acinar cells that secrete the pancreatic digestive enzymes into the pancreatic duct Endocrine pancreas - it is the islets of Langerhans that secrete insulin and glucagon into the blood stream

Question 24

One of the reasons for pain arising from the pancreas is secondary to inflammation - pancratitis What are the different causes of pancreatitis? (GET SMASHED) Where is pain felt and where can it radiate to?

Answer 24

Pancreatitis Gallstones, Ethanol (alcohol), Trauma, Steroids, Mumps, Autoimmune, Scorpion bites, Hyperlipidaemia / hypercalcaemia, ERCP, Drugs Pain is usually felt epigastric and/or umbilical, can radiate to patients back

Question 25

The small intestine consists of the duodenum, jejunum and ileum What is the different length of each part? Which parts are foregut and which are midgut?

Answer 25

Duodenum - approx 25cm Jejunum - approx 3m Ileum - approx 4m Foregut - 1st and 2nd part of duodenum, rest of small intestine is midgut

Question 26

What are the different parts of the duodenum? What does the 4th part lead into? State which parts of the duodenum and pancreas are intraperitoneal or retroperitoneal?

Answer 26

Duodenum Intraperitoneal 1 - Superior - Retroperitoneal 2 - Descending 3 - Horizontal 4 - Ascending - leads into the duodojejunal flexure Pancreas is a retroperitoneal except the tail -\> intraperitoneal

Question 27

What is the blood supply to the pancreas and the duodenum? (state where the arteries arise) (remember both organs are is half foregut, half midgut)

Answer 27

Blood supply to pancreas Pancreatic branches from the splenic artery To pancreas + duodenum Superior pancreaticoduodenal branch of the gastroduodenal artery (branch of the common hepatic artery) Inferior pancreaticoduodenal branch of the superior mesenteric artery

Question 28

What is the purpose of the pyloric sphincter? What does sympathetic and parasympathetic innervation do to sphincters and motility?

Answer 28

Pyloric sphincter is an anatomical sphincter controlling the flow of chyme from the stomach to the duodenum Sympathetic innervation - contraction of sphincter smooth muscle and decreases motility Parasympathetic innervation - relaxes the sphincter smooth muscle and increases motility

Question 29

Where does the jejunum begin? Where does the ileum end? Which quadrant are they found in?

Answer 29

Jejunum begins at the duodojejunal flexure Ileum ends at the ileocaecal junction Small intestine found in all four quadrants

Question 30

How does the mucosa of the jejunum and ileum differ? What are the folds known as in the small intestine? - what is their function?

Answer 30

The mucosa of the jejunum is highly folded - these folds are known as plicae circularis The mucosa of the distal ileum is much smoother The function of the plicae circulares, the villi, and the microvilli is to increase the amount of surface area available for the absorption of nutrients

Question 31

What is the blood supply to the jejunum and ileum? What is the venous drainage? What do the vessels travel within?

Answer 31

Blood supply is from the superior mesenteric artery via jejunal and ileal arteries Venous drianage is from jejunal and ileal veins to the superior mesenteric vein to the hepatic portal vein The vessls travel within the mesentery

Question 32

Why is bile secreted from the gallbladder after eating? what cells does bile act on? and what happens to these cells? - where do they eventualy drain?

Answer 32

Bile is secreted from the gallbladder after eating as the duodenum releases the hormone cholecystokinin The bile emulsifies fats and this is absorbed into specialised lymphatic vessels of the small intestines called lacteals They travel via the lymphatic system to eventually drain via the thoracic duct in the left venous angle

Question 33

What do lymph vessels of the abdomen tend to lie alongisde? What are the main groups of lymph nodes draining abdominal organs? - which drain the foregut, midgut and hindgut organs?

Answer 33

Lymph vessels in the abdomen tend to lie alongside arteries (in the limbs it is alongside veins) Main groups Coeliac nodes (foregut organs) Superior mesenteric nodes (midgut organs) Inferior mesenteric nodes (hindgut organs) Lumbar nodes - kidneys, posterior wall, pelvis, lower limbs