Flashcards in 1 - Anatomy & Histology of the Liver Deck (73)
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1
Normal Liver Mass
1500g
Largest organ
2
Normal Portal Pressure
5 - 10 mm Hg
Low pressure
3
Hepatocytes - Do they all do the same thing?
No!!!!
They have functional heterogeneity
4
Liver's borders
Right 5th rib
Left 6th rib
Right 9th rib
Feel it below the 9th rib and it's HUGE!!!!!!
5
Contents of the portal vein
Collection of venous blood from spleen, splenic vein, SMA, IMA
6
Portal Hypertension
Obstruction to portal vein flow causing pressure to increase above 10mm Hg
7
Post-Hepatic Hypertension
Rarest kind of portal HTN
Congenital webs of the IVC
8
Intra-Hepatic Hypertension
Most common type of portal HTN
Cirrhosis
Other types of pathology
9
Pre-Hepatic Hypertension
Thrombosis blocking entry to the portal vein
10
How many lobes?
2!
11
Components of the liver
2 Lobes
Glisson's Capsule (smooth! IT IS SMOOTH!!)
Falciform Ligament
12
Real divisions of the liver
8 Segments
4 on the left, 4 on the right
Each has its own vascular and biliary pedacle
13
Two sources of blood for the liver
Celiac Trunk > Hepatic Artery > Left & Right Lobes
Splenic Vein + IMA + SMA > Portal Vein
14
Biliary Tree
Bile conducted from ducts inside into common hepatic duct which meets with cystic duct to join the GI tract
15
Lobule
One functional unit of hepatocytes.
Central vein in the center
Arterial flow at the periphery
No connective tissue divisions between lobules the way pigs do!!!
16
Central veins
Marked by venous endothelium
17
Portal tracts
Collagen tracts that carry 3 tubes:
Bile duct
Artery
Vein
Can fibrose in pathways leading to other portal tracts when inflammation fucks that shit up
18
Blood path through a lobule
Portal tracts at periphery
Contents flow through sinudoids in the periportal regions
Undergo hella changes
Enter central veins to go back to the heart.
19
Bile Cannaliculi
Collect bile, interanastomose and form the canal of herring, which drains into the individual bile ducts that drain into the hilum and the common bile duct.
20
Where do the progenitor (stem) cells in the liver live?
The Canal of Herring
21
Description of Lobule
Radiating Cords
Nicely organized
Once Cell Thick (so nicely bathed)
22
Central Veins
Anastomose into Hepatic Veins (R & L)
Exit to IVC
23
Portal Tract on Histo
Nothing but collagen, fibroblasts and triad of structures
Inflammatory
24
Bile Duct
Tube of cuboidal epithelium
25
Limiting Plate
The hepatocytes at the edge of the Portal Tract
Chronic Hepatitis - Lymphocytes and inflammatory cells can infiltrate this structure and cause fibrosis
26
Mixing of Portal Venous and Hepatic Arterial Blood
Hepatic artery branches give off small twigs which empty arterial (oxygenated) blood into the periportal sinusoids directly outside the portal tract connective tissue
27
Chronic Hepatitis
Ground Glass Inclusions
Lymphocytes and other inflammatory cells cross limiting plate
28
Space of Disse
Type III Collagen
Discontinuous Array
29
Least oxygenated hepatocytes
Right around the central vein
They die quickly because they receive the least-oxygenated blood
30
Lipofuscin Pigment
Phagolysosomes with "Wear & Tear" cell debris
Brown Pigment Junk
Appears in Heart, Liver, and Adrenal. Myocytes particularly.
See it first in the hepatocytes surrounding central veins
31
Areas from Portal Tract to Central Vein
Periportal
Midzonal
Centrilobular
Each is about 7 cells wide
~22 hepatocytes from portal tract to central vein
32
Periportal Area - Zone 1
Best oxygen
Oxygen tension is 65mm Hg
Area where chronic hepatitis is most active
Gluconeogenesis
Bile Salt Synthesis
33
Centrilobular Area - Zone 3
Oxygen tension is 35 mm Hg
Furthest from oxygen
Most vulnerable to shock/ischemia
Contains drug metabolizing enzymes
Cytochrome p450s
Area where alcohol is metabolized
34
Acinar Zones
Another interpretation of
Zone 1 - Best perfusion
Zone 2 - Midzonal
Zone 3 - Centrilobular
35
Zone 1
Chronic Hepatitis
NH3 Metabolism (OTC & CPS Enzymes
36
Midzonal - Zone 2
Protein Synthesis
37
Zone 3
Drug Metabolism
Ischemia/Shock
Glutamine Synthetase Enzyme
38
Pit Cell
Natural Killer Cell
Tumor Surveillance
Tumor cells from GI tract come back in portal vein
Pit cells KILL THOSE BITCHES
39
Kupffer Cell
Macrophages
Contain multiple pseudopodia
Lie in waiting along endothelial surfaces
Phagocytose microbes
40
Endothelial Cells
Contain fenestrae in the sieve plate
Allow smallecules to move from Sinusoids into the Space of Disse
41
Space of Disse
Contains scattered discontinuous Collagen III fibers
Contains Ito (Stellate) cells
No basement membrane
Low pressure system (Dependent on how tight or loose the endothelial cells are, or how tight or loose stellate cells are
42
Stellate (Ito) Cells
Chief fibrotic source for the liver
Stores vitamins
Lies in wait for liver damage
Releases collagen on damage
Have little triangular basophilic nuclei (like little hats) over a vacuole of Vitamin A (fat soluble)
43
Canal of Hering
Bile canalliculi narrow to tubes lined by single cuboidal epithelium as they approach the bile ducts.
Progenitor cells live in that part
They can differentiate into whatever types of cells you need!!
44
Overdose of Vitamin A
Hyperplasia in Space of Disse
45
Endothelin and NO
Released in order to modify tension of endothelial cells and stellate cells
46
Bile Pumps
There are different bile pumps in the canaliculi
Studying these will reveal new forms of jaundice
BSEP
FIC-1
OATP
47
BSEP
Bile Salt Exporter Pump
Inhibited if you have septic shock from LPS
48
FIC-1
Familial Intrahepatic Cholestasis-1
Causes of jaundice in the liver itself
49
OATP
Organic anion transport pump
50
Cholestasis
Impaired bile secretion
51
Jaundice
Sallow yellow skin
Icteric sclera
52
LFTs
Liver Function Tests
Total Protein
Albumin
Globulin
Bilirubin Total
Bilirubin Direct (conjugated)
Bilirubin Indirect (unconjugated)
AST
ALT
Alk Phos
53
Total Protein
6.7 - 8.6 g/dL
54
Albumin
3.5 - 5.5 g/dL
55
Globulin
2.0 - 3.5 g/dL
56
When a hepatocyte dies, what is released?
AST/ALT
57
Pressure on bile ducts and canaliculi?
Elevated Bilirubin/Direct bilirubin
Alk Phos goes up
GGT (gammaglutamyl transferase)
5'NT (5' nucleotidase)
58
Synthesis
Synthetic proteins
Total Protein
Albumin
59
Synthesized in hepatocytes
Clotting Factors (I - II - V - VII - IX)
Albumin
Complement Proteins
60
Largest grey thing on EM
Erythrocytes
61
How does the liver regenerate?
Like medusa
62
How often do hepatocytes divide?
Every 400 Days
63
How many times can a hepatocyte divide?
70 Times
64
Regeneration after injury
Cell Division (eg hepatitis)
65
Severe Loss of tissue - Regeneration
From progenitor cells! (eg fulminant hepatitis)
66
Cirrhosis
An example of ABNORMAL REGENERATION with abnormally thick liver-cell plates
Cords are no longer 1 cell thick, but 3 or 4 cells thick
Blood can't squeeze through!! THAT SUXXXX
Portal fibrosis
67
Embryonic origins of liver
Gut ectoderm
68
Septum transversum
Primitive diaphragm running horizontally
Gut from narrow tube growing into connective tissue plate
69
22 Days post-blastocyst
Foregut endoderm goes into septum transversum.
Vitelline veins go into sinusoids
70
26 days post-blastocyst
Cystic Bud
(Cystic duct & gall bladder)
71
7 - 8 weeks
Portal vein
Portal tract
Sinusoids
Liver cords (many cells thick)
72
9 - 10 weeks
Bile duct plates (BDP) develop
Differentiation of periportal hepatocytes to bile duct epithelium (bile duct plate)
73
