Anatomy of the Liver Flashcards
What is the largest organ in the abdominal cavity, and where is it located?
- liver
- upper right (mainly) and left quadrant
What are some of the basic functions of the liver?
- digestion
- metabolism
- detoxification
- bile production
- glycogen storage
How many regions are in the abdomainl cacvity?
- 9
What are the upper 3 regions of the abdomen called fro right to left?
1 - right hypochondriac region
2 - epigastric region
3 - left hypochondriac region
What are the middle 3 regions of the abdomen called fro right to left?
1 - right lumbar region
2 - umbilical region
3 - left lumbar region
What are the lower 3 regions of the 9 regions of the abdomen called from right to left?
1 - right inguinal region
2 - hypogastric region
3 - left inguinal region
What does topography mean?
- study of an organ based on regions
- emphasises the relationships between organs and tissues
How many main lobes does the liver have?
- 2
- left and right (right is bigger)
What are the superior and inferior borders or the liver called?
- superior = diaphragmatic surface
- inferior = visceral surface
What are the 2 accessory lobes of the liver called?
1 - quadrate
2 - caudate
What is the large white struction on the anterior section of the liver and what role does it have in providing stability to the livers anatomical position?
- falciform
- attaches liver to anterior wall of abdomianl cavity
What is the falciform on the anterior aspect of the liver formed from?
- a fold from the peritoneum
The ligamentum teres (round ligament) is an attachment to the falciform ligament on the anterior section of the liver. What is this a remnant of?
- umbilical cord
What is the liver covered with?
- capsule
- peritoneum
What is the hilum of the liver called?
- porta hepatis
What passes through the hilium of the liver called the portal hepatis?
- portal vein
- hepatic artery proper
- common hepatic duct
- nerves and lymphatics
The falicorm opens up and covers the liver and then reflects onto the under surface of the liver forming triangle ligaments areas on the left and right side of the liver. How do these triangular ligaments provide structure to the liver?
- anchor the superior aspects of the liver to the diaphragm
The falicorm opens up and covers the liver and then reflects onto the under surface of the liver forming the lesser omentum. What is the lesser omentum?
- double fold of peirtoneum
- attaches the liver to the stomach and duodenum
The coronary ligaments (anterior & posterior layers) are formed from the triangula ligaments as the peritoneal folds over the liver. What do the coronary ligaments attach to, to help provide support to the liver?
- attaches the superior surface of the liver to the inferior surface of the diaphragm
What is bile, and what produces bile?
- dark-green-to-yellowish-brown fluid
- produced by the liver
- stored in the gall bladder
Once the hepatocytes have created the bile, how does it make its way into the gall bladder?
- bile canaliculi join to form left and right hepatic ducts
- left and right hepatic ducts converge into common hepatic duct
- common hepatic duct merges with cystic duct
- cystic duct merges with common bile duct
The common bile ducts connects the gall bladder, which can then connect to what providing bile to the GIT?
- duodenum
How much of the blood in the liver is in the arterial and venous blood vessels?
- arterial = 25%
- venous = 75%
The liver is located in the foregut, what are the main artery and veins supplying the foregut?
- coeliac artery
- portal vein
What are the 3 main branches of the coeliac artery?
1 - left gastric supplies stomach
2 - splenic supplies spleen
3 - hepatic supplies liver
Which blood vessels that originates in the coeliac artery and supplies blood including nutrients and O2 to the parenchymal liver tissue?
- hepatic artery proper
The largest vein in the body supplies blood to the liver, what is this vein called?
- portal vein
- it is valveless
Blood arriving into the liver via the largest vein in the body, the portal veing comes from where?
- inferior and superior veins
- splenic vein
- brings blood from digestive tract into the liver
The blood arriving in liver via the portal vein is deoxygenated, but what does it contain a lot of?
- nutrients from the GIT
- toxins from the GIT
- drugs from the GIT
What are the functional cells of the liver called, and how much of the liver do they make up?
- hepatocyes that make up lobules
- make up 60% of the liver
What are hepatic sinusoids?
- sinusoidal capillaries
- discontinuous endothelium that mix blood
- feed into the central portal vein
At each corner of the hexagon there is a portal triad that contains 3 structures. What are these 3 structures?
1 - arteriole
2 - venule
3 - bile duct
- lymphatic and nerves are present here as well
What are Couinaud segments in the liver?
- system to divide the liver into eight independent functional units (termed segments)
- parts of liver can be removed easily
Why does the liver need the 8 Couinaud segments?
- each segment has its own vascular inflow, bilary and lympahtic
- similiar to lungs
The blood in the sinusoids will drain into the centre of each hexagonal subunit and into the central vein. From the central vein how does the blood reach the heart?
- central vein into collecting veins
- collecting veins into hepatic veins
- hepatic vein into inferior vena cava
Where does the right and left hepatic artery carry blood into?
- liver
Why is damage to the lower ribs that cause a penetrating injury be dangerous to a large organ in the upper right quadrant?
- could penetrate the liver
- high vascularised so high risk of haemorrhage
Any that is absorbed from the GIT has to pass through which organ?
- the liver
What is the portal venous system?
- venous blood system draining the GIT, spleen and pancreas
- merges into the portal vein and enters the liver
- all deoxygenated blood
What is the porto-systemic anastomosis also known as portocaval anastomosis?
- porto refers to portal system
- caval refers to great veins like vena cava
- communication between the portal and the systemic venous system
What is the purpose of the porto-systemic anastomosis also known as portocaval anastomosis?
- help if the portal system is blocked
- portocaval anastomosis enable the blood to still reach the systemic venous circulation despite portal system blockage
If the liver is damaged (cancer, hepatic portal hypertension, etc..) how do the porto-systemic anastomosis help, and how can this present?
- divert blood away from portal vein if it is damaged/blocked
- presents as varicose veins (venous dilations)
Why can varicose veins (venous dilations) present in patients with liver disease?
- portal system becomes blocked/damaged
- pressure builds up and veins dilate to accomadate
There are 4 major porto-systemic anastomosis sites that we need to be aware of in the body. What is the abdominal part of oesophagus porto-systemic anastomosis?
- left gastric vein (portal) merges with oesophageal branches of azygos vein (systemic)
There are 4 major porto-systemic anastomosis sites that we need to be aware of in the body. What is the upper anal canal part of the porto-systemic anastomosis?
- lower end of the rectum
- superior rectal (portal vein) anastomoses with middle and inferior rectal veins (systemic)
There are 4 major porto-systemic anastomosis sites that we need to be aware of in the body. What is the umbilical area of the porto-systemic anastomosis?
- umbilicus
- paraumbilical veins (portal) anastomosis with epigastric veins (systemic)
There are 4 major porto-systemic anastomosis sites that we need to be aware of in the body. What is the etroperitoneal veins of colon area of the porto-systemic anastomosis?
- posterior abdominal wall
- duodenum, pancreas, liver (portal) anastomosis with renal, lumbar and phrenic, bare area of liver (systemic)
What are osophageal varices, and what causes them?
- enlarged veins in the esophagus
- generally due to obstructed blood flow through the portal vein
- suspect liver disease
What are heamorrhoids, and what causes them?
- swollen veins in your lower rectum
- can be caused by blocked portal vein
- suspect liver disease
What is umbilicus caput medusae, and what is likley to cause this?
- enlarged superficial epigastric veins
appear from the umbilicus
- suspect liver disease
What is the flow of lymphatics from the liver to the cisterna chyli?
- superficial and deep lymphatic of liver (local)
drain into ⬇️
- lymph nodes at porta hepatis (regional)
drain into ⬇️
- coeliac nodes (terminal)
drain into ⬇️
- Cisterna chyli
