Liver Anatomy Flashcards
what is the largest gland in the body
the liver
where does the liver sit
- Sits under the right dome of the diaphragm and is covered by the ribcage so cannot be palpated
how do you palpate the liver
- The diaphragm moves it down on inspiration, this pushes the liver down, in order to palpitate the liver only on inspiration so it is moved down underneath the ribcage
describe the lobes of the liver
Anteriorly
- Have a left and right love
- Right lobe is larger
Posteriorly
- Has 4 lobes
- Left lobe
- Right lobe
- Caudate lobe
- Quadrate lobe
what are the two lobes of the liver between the left and right lobe
- caudate lobe
- quadrate lobe
the caudate lobe is…
above the quadrate lobe
is the liver retroperitoneal or intraperiotenal
intraperiotenal
what is the blood supply of the liver
75% hepatic portal vein
25% hepatic artery proper
name the ligaments of the liver
- falciform ligament
- anterior coronary ligaments
- posterior coronary ligaments
- right and left triangular ligament
- ligamentum teres (or round ligament of the liver)
describe the ligaments of the liver
- anteriorly there is the falciform ligament, when you look at the liver from the top the falciform ligament splits into two these are called the anterior coronary ligament
- you also have a posterior coronary ligament
- where the anterior and posterior coronary ligament meet you have left and right triangular ligaments
- there is also the ligamneutm trees this is an mbryologicla remnant of foetal circulation of the ductus venous, this fibrosis and becomes the round ligament fo the uretuers (ligaments tires)
what is between the coronary and triangular ligaments
- Between the coronary and triangular ligaments, you have an area on the top of the liver that isn’t covered by peritoneum and this is called the bare area - this is because it grows too quickly so is not covered by peritoneum
where does the round ligament of the liver run
- it runs between the left lobe and quadrate lobe
where’s does the origin of the lesser momentum begin
- it is between the caudate lobe and the left lobe
what does the lesser omentum attach
- it attaches the liver to the lesser curvature of the stomach
what is within the origin of the lesser omentum
the porta hepatis
what three things make up the porta hepatis
- hepatic portal vein
- hepatic artery proper
- common bile duct
what does the greater onetime attach
attaches the liver to greater curvature of the stomach
what happens if you have any bleeding from the vessels in the porta hepatis
if you have bleeding from any of those vessels you can clamp the free border of the lesser omentum as this is where they go through
describe the hepatic portal circulation
- deoxygenated blood from the digestive tract passes to the liver via the hepatic portal vein before returning to the heart via the IVC
- this is where glucose is stored, detoxification of drugs and other substance happens
- then the hepatic vein goes into the IVC which takes the deoxygenated blood to the heart
where does the arterial blood supply of the liver originally come from
coeliac trunk
- then branches into the hepatic artery proper which supplies the liver
what levels is the
- coeliac trunk
- superior mesenteric artery
- inferior mesenteric artery
- T12
- L1
- L3
what does the coeliac trunk split into
three branches
- splenic
- left gastric artery
- common hepatic artery
- splenic – runs behind the stomach very torturous goes to the spleen, gives of the right gastric and left gastroepiploic atery
left gastric artery - this supplies the lesser curvature of the stomach - gives of oesophageal branches which supply the oesophagus
common hepatic - gives of gastrodudoenal and right gastric, then becomes the hepatic artery proper
what does the superior mesenteric artery split into
- Supplies the ileocolic arteries
- Jejunal and ileal branches
- Right colic arteries
- Middle colic
- MRI – middle colic, right colic, ileocolic
what does the inferior mesenteric artery split into
- Left colic
- Sigmoid
- Superior rectal
where does the superior mesenteric artery and inferior mesenteric artery join
- they join and they form marginal branches
what does the hepatic artery proper split into
- right and left hepatic arteries
what is the venous drainage of the
- foregut
- midgut
- hindgut
- Foregut - splenic vein
- midgut - superior mesenteric
- hindgut - inferior mesenteric
what are the branches of the inferior mesenteric vein
- superior rectal vein
- sigmoidal vien
- left colic vein
what are the branches of the superior mesenteric vein
- iliocolic
- middle colic
- right colic
- jejenunal and illegal branches
describe sinusoid circulation
- Have branches of hepatic portal vein, branch of hepatic artery and bile duct
- Blood from hepatic portal vein passes through the sinusoid which drain into the central veins to the hepatic veins to the IVC
what is cirrhosis of the liver
- it is a consequence of chronic liver disease that is characterised by replacement of liver tissue by fibrosis, scar tissue and regeneration nodules lumps occur as a result of a process in which damaged tissue is regenerated leading to loss of liver function
what happens to sinusoid channels in cirrhosis of the liver
- they get broken up and they are no longer straight therefore there is increased resistance to blood lobe through the liver and an increase resistance in the portal vein
what are porto-canal anatomises
- these are where you have at certain points anatosmosies where the structure can either drain into the systemic circulation(IVC) or the portal circulation ( hepatic portal vein)
What are the 4 porto canal anatomoses
- oesophagus
- retroperiotenal
- rectum
- umbilical
describe the porto-caval anastomoses for the oesophagus
- portal = Left gastric vein
* systemic = Azygos vein
describe the porto-caval anastomoses for the retroperiotenal
- portal = Duodenal, pancreatic, right and left colic veins
* systemic = Lumbar veins
describe the porto-caval anastomoses for the rectum
- portal = Superior rectal vein
* systemic = Inferior rectal vein (internal iliac)
describe the porto-caval anastomoses for the umbilical
- portal = Paraumbilical veins (Falciform ligament recanalized)
- systemic = Intercostal and inferior epigastric veins
- This anastomoses only forms with raised hepatic portal pressure, this vessel can recanulaise if there is increased hepatic portal pressure
what portal caval system only forms with raised hepatic portal pressure
- umbilical
what is a clinically relevant sign of the portal caval anatsomeoss for the oesophagus
- blood starts to pass through the small vessels and then they dilate, dilation of the veins are called varices - these increase in size until they rupture and bleed
- oesophageal varices are a clinical sign of this
what are oesophageal varices present with
haematemesis
- Variceal bleeding is the most sever compoiation of cirrhosis and is the second most common cause of mortality among patients
How do you treat oesophageal varices
- can be treated with oesophageal banding
what is caput medusae
this is when umbilical poroto caval anatomosise opens up
- only occurs when hepatic portal pressure is increased
- the intercostal and inferior epigastric veins radiate from the umbilicus and show on the abdomen
what is ascites
fluid in the peritoneal space
what can cause ascites
- portal hypertension
- hypoalbuminemia
- aldosterone related renal sodium retention, with consequent blood volume expansion (further exacerbated by additional pressure on kidneys)
how does portal hypertension cause ascites
- portal hypertension increases capillary hydrostatic pressure which increases lymph formation in the interstitial tissues which leads to ascites
- or
- portal hypertension increases production of vasodilators which leads to splanchnic arteriolar vasodilation this reduces blood pressure and triggers the activation of the sympathetic and renin angiotensin aldosterone system which leads to sodium and water retention which leads to an increase in plasma volume expansion and therefore ascites
where does the superior rectal vein drain
- drains into the inferior mesenteric vein
where does the inferior and middle rectal vein drain
- ## drains into the internal pudendal vein which is a branch of the internal iliac vein
where else can you develop varices
in the rectum
what can cause splenomegaly
- increased hepatic portal pressure means that you back blood up
- back blood up to the splenic vein and into the spleen therefore you can get an increased size of the spleen this is splenomegaly
describe the biliary tree
- have the right hepatic duct and left hepatic duct
- come together and form the common hepatic duct
- off of the hepatic duct is the cystic duct which branches to the gall bladder
- when the cystic duct and common hepatic duct join these form the common bile duct
- enters the pancreas via the hepatopancreatic ampulla
- major duodenal papilla is the hepatopancreatic ampulla
- minor duodenal papilla
if gall stones are in the gall bladder do you get any symptoms
- often asymptomatic
- problems start when the gall stones move out of the gall bladder into the capillary ducts
describe the type of pain experienced with gall stones
- if the gall stones re in the biliary colic - there is transient pain so pain is not present all the time
- if there is inflammation of the gallbladder due to bile flow obstruction this leads to acute cholechytsisi which is constant pain
how do you test for gallbladder inflammation
test for this is when you push the gallbladder down onto your hand and it is inflamed – this is called murhys sign
what is a side effect of gallstones
- can become jaundice
- this happens when bilirubin in bile is not able to be broken down as the bile is being blocked from leaving the gall bladder
what happens in the gallstones get lodged in the pancreatic duct
Stone blocks bile and pancreatic ducts, stopping flow of bile and pancreatic enzymes.
Causing biliary colic, jaundice and pancreatitis
