3A Anatomy of the Liver Flashcards
The liver consists of which four lobes?
Right, left, quadrate, and caudate lobes
The lobes are composed of what functional units?
Lobules
Which lobe is the largest?
Right lobe
T/F The liver is encased in the ribcage?
T
What divides the right and left lobes?
The falciform ligament
Where is the caudate lobe positioned on the liver?
Posterior-superior (not inferior as the word caudate would imply “tail”)
Where is the quadrate lobe in relation to the caudate lobe?
Inferior of the caudate lobe
Do the different lobes have different functions?
No, they all have the same function
What shape do lobules look like?
Hexagon
What do lobules consist of?
Rows upon rows of hepatocytes.
How does blood flow past hepatocytes?
Via sinusoids from branches of the hepatic portal vein to the central vein of each lobule
What is at the center of the lobule hexagon?
Central vein
What separates the lobules?
CT
Which lobules have thicker CT, human or pig?
Pig
What makes up the poral triads (tetrads really) at the corners of the lobule hexagon?
Portal vein branch, hepatic artery branch, bile duct, and lymphatic vessel
The portal system carries blood from where?
Intestines
T/F The venous and arterial blood flow in the same direction past the hapatocytes and mix
T
What does the venous blood carried in the portal vein have a lot of?
Nutrients! The liver is the first to see blood that has absorbed nutrients from the intestine
What do Kupffer cells do?
They are hepatic macrophages so they remove debris such a bacteria and worn out blood cells
What are the tiny ducts that run parallel to the sinusoids?
Bile canaliculi and drain bile produced by the hepatocytes
What are hepatic cords?
Hepatocytes arranged into cords separated by adjacent sinusoids
T/F The liver has two blood supplies
T - oxygenated blood from hepatic artery and deoxygenated by nutriet-rich blood from the hepatic vein
Where do the two blood supplies mix in the liver?
Liver sinusoids
What is the sequence of blood thru the liver and out?
Liver sinusoids, central vein, hepatic vein, inferior vena cava,right atrium of heart
What are sinusoids lined with?
Fenestrated endothelium
Does the sinusoid endothelium have an underlying basement membrane?
No, therefore the fenestrations permit blood plasma to wash freely over the exposed surfaces of the hepatocytes
What is the space of disse?
Perisinusoidal space where blood washes freely coming the fenestrations in the sinusoid epithelium
T/F Liver capillaries are very leaky
T
Why are liver capillaries very leaky?
So you can supply lots of oxygen and lots of nutrients
Why does the liver have a lot of lymphatics?
Do drain away the interstitial fluid created the very leaky sinusoidal epithelium
What organ has the highest supply of lymphatic vessels than any other organ in the body?
Liver
What is the interstitial space in the liver called?
Space of disse
Sinusoidal blood flow is always in what direction?
Towards the central vein
What happens if excessive amounts of fluid being to transude into the lymph and leak thru the outer surface of the liver capsule directly in to the abdominal cavity?
Ascites
T/F Healthy men have little or no interperitoneal fluid, but women may normally have as much as 20 mL depending on the phase of the menstrual cycle
T
Whys is the liver a prime site for the spread of cancerous cells from elsewhere in the body?
B/c of its portal blood supply and extensive lymphatic circulation
Metastasis of cancer to the liver is especially likely from what three areas?
GI tract, breast, and lung
What is the first pass effect?
Most drugs absorbed from the GI tract enter the portal circulation and encounter the liver before being distributed into general circulation
What if a drug has 100% first pass effect?
It will be completely filtered out and not get into the arterial blood (you’d have to give it subcutaneously or intramuscular)
What is the sequence of the bile flow from the liver?
R/L hepatic ducts, common hepatic duct, common bile duct
