Liver Flashcards
1
Q
Flow of fluids into and out of the liver lobule
A
- On the periphery of the liver lobule there is a hepatic artery and portal vein which both enter the lobule
- their blood mixes together in a sinusoid
- Flows down the central vein where it extis the lobule through hepatic vein
- Flowing in the opposite direction (out to periphery)
- -Bile fluid in bile ducts
- -Some lymphatic vessels also flowing out of the lobule
2
Q
Portal Triad
A
- Hepatic Arteriole
- Portal Venule
- Bile Ductule- Hering’s Canal
- Lymphatic vessel
3
Q
Hepatic Sinusoids
A
- Both arterial and portal blood mix in the sinusoids as they flow towards the central vein
- holes in the endothelial lining of the sinusoid
4
Q
Hepatocytes
A
- main cell type of the liver
- Sinusoidal face contains an abundance of microvilli
- -increases surface area
- -help absorb the components of blood into the liver
- two adjacent hepatocytes from the bile canaliculus through tight junctions
Roles
- Synthesis of plasma proteins (albumin, fibrinogen)
- Storage of glucose as glycogen
- convert amino acids into glucose
- detoxification and conjugation of ingested toxins
5
Q
Space of Disse
A
- Immediately adjacent to hepatocytes
- between hepatocytes and fenestrated epithelium
6
Q
Kupffer Cells
A
- derived from monocytes
- phagocytic - phagocytize foreign materials and aged red blood cells in sinusoids of the liver
- mainly in sinusoids
7
Q
Ito Cells
A
- Fat storing cells
- play a role in fat storage
- play a role in disease (cirrhosis of the liver)
- -secrete a lot of type I collagen under disease
- -leads to cirrhosis of thel iver
- -cirrhotic liver = too much connective tissue
- tend to be in the space of disse
- also called lipocytes
- also called hepatic stellate cells
8
Q
Somatomedins
A
- IGF’s
- Make their way to cartilage
- stimulates proliferation of chondrocytes and chondroblasts
9
Q
Extra Medullary Hematopoiesis in the liver
A
- If you have damage to bone marrow
- Secondary hematopoiesis in the liver
- related to fetal function of the liver (hepato/spleno/thymic phase)
10
Q
Formation of Bilirubin
A
- Kupffer cells - taking up aged red blood cells
- Hemoglobin is stripped of heme molecule by the macrophages
- globin is broken down into amino acids and is recycled
- heme is stripped of iron which is recycled - Heme is converted to biliverdin
- via heme oxygenase - Biliverdin is further catabolized to bilirubin
- Bilirubin is released by macrophage and taken up by liver
- bound to albumin and taken up by the liver - In the liver
- Bilirubin is made into bilirubin glucuronide via glucuronyltransferase
- more water soluble
- What is excreted into bile canaliculus and makes its way into the gall bladder and large intestine
11
Q
Bile Canaliculus
A
- made via tight junctions of adjacent hepatocytes
- bile is running through this to the periphery of the liver (opposite direction as blood)
- bile acids such as cholic acid are synthesized in hepatocytes and secreted into the bile canaliculus
12
Q
Classic Lobule
A
- portal triad
- arteriole and venous blood flowing to central artery
- the bile canaliculus and lymphatics flowing back out
13
Q
Portal Lobule
A
- Bile flowing from center to portal triad
14
Q
Portal Acinus
A
- Most oxygenated zone (zone I) is where the portal triads are due to the blood vessels
- As you flow from triad to central vein there is a reduction of oxygen concentration
- Central vein will have the least amount of oxygen
- Zone I is most oxygenated
- Zone II is least oxygenated
15
Q
Pit cells
A
- NK cells
- in the sinusoids
