Liver and Pancreas Flashcards
Liver receives blood from? Known as ____ vessels.
AFFERENT
- Portal vein - nutrient rich, oxygen poor—70-80%
- Hepatic artery–oxygen rich–20-30%
Glisson’s capsule
FIBROconnective (type III collagen) tissue capsule that divides liver in lobes and lobules
SIMPLE SQUAMOUS
Functions of the liver
- gluconeogenesis
- detoxification (via conjugation and oxidation and stuff)
- Storage- fat, glycogen, fat soluble vitamins (ADEK)
- Bile production in sER (EXOCRINE)
- Plasma protein synthesis (ENDOCRINE)
- transfer of IgA into bile canaliculi
What are some serum proteins the liver makes?
Endocrine= fibrinogen, prothrombin, albumin, c- reactive protein. Also makes urea for excretion.
Blood exits liver via (AKA ___ vessels)
EFFERENT
central vein
Main cell of the liver
- Shape
- stain
- organelles
Hepatocytes=parenchymal cells
- Polyhedral epithelial cells
- eosinophilic cytoplasm (rich in mitochondria)
- Large round central nuclei (sometimes binucelate), with abundant rER, sER, lysosomes, peroxisomes, and funky microvilli on side with space of disse AND
- glycogen deposits and lipid droplets
parenchymal cell-definition??
Looked this up, it means its a functional cell rather than a structural cell. FYI.
Stroma= Structural, CT
hepatocyte DNA-significance?
can be diploid or polyploid. Liver cells will divide if part of liver is removed.
Hepatocyte arrangement (classic)
HEXAGONAL arrangement of hepatocyte plates around central vein
Portal canal= ____ = ___
Contains?? ?
Portal canal= portal triad= portal area
Branches of portal vein, hepatic artery, bile duct. Sometime lymph
Location of portal canal
found at periphery of lobules.
Flow of blood in portal areas?
INTO liver sinusoids –> central vein
Liver sinusoids
- location
- features
- Cells
- Blood found here?
- spaces between hepatocyte plates
- Lined with fenestrated endothelial cells and NO BASAL LAMINA
- KUPFFER CELLS
- Mixed venous and arterial
Another “space” between liver cells. (between the sinusoids and hepatocyte)
- Contains
- Function (x2)
Space of Disse
1. filled with plasma, Ito cells, and reticular fibers
2.
A. microvilli (*irregular) of hepatocytes “bathed” in plasma = exchange of material between blood and hepatocytes.
B. Vitamin A storage in Ito cells
Kupffer cells (aka?)
- location, shape
- function (X3)
- lineage
AKA stellate macrophages
1. sinusoids lining, crescent shaped
2.
A. phagocytose old RBC which frees Fe and Heme for reuse or storage in ferritin.
B. Antigen presenting cells that get rid of debris
C. Can release cytokines that induce collagen production in stellate cells.
3. monocytic lineage
Stellate macrophages vs hepatic stellate cells
DONT MIX THESE UP
stellate macrophages are Kupffer cells found in sinusoids responsible for macrophaging.
Hepatic stellate cells are in the space of Disse= perisinusoidal space and are responsible or vit A storage and making ECM
What helps “free” iron and heme? what happens when they’re freed?
Kupffer cells free them from old RBC. they bind ferritin or are reused.
Hepatic stellate cells (AKA)
- Location
- Function
- Characteristics
AKA cells of Ito
- Space of Disse/perisinusiodal space/subendothelial space
- Store Vit A (and other fat-sol vits); make ECM and collagen in response to cytokines (from kupffer and hepatocytes)
- small lipid droplets in them (have the vit A)
Models of liver organization
- Classic lobule
- Portal lobule
- Hepatic acinus
Classic lobule
- Arrangement
- Flow of material
- hepatocytes organized hexagonally around central vein.
2. into central vein
Portal lobule
Based on 3 central veins and one portal area. triangle is flow of bile into bile duct
Hepatic acinus
AKA Acinus of Rappaport
2 central veins= oval/diamond area with metabolic gradient. Zone 3= drainage zone
Zone 1= periportal zone
Apical side of hepatocyte vs basolateral side.
Apical= bile canaliculi Basolateral= process nutrients and stuff from blood
Within a lobule, how does the function of a central hepatocyte differ from the peripheral hepatocyte?
Peripheral hepatocytes are near portal area and get more O2 allowing them to make proteins, cholesterol and gluconeogenesis. Central hepatocytes have less nutrients and O2 and work more on detox and glycogen metabolism.
Hepatocytes in Zones 1-3?
Zone 1= oxidative functions
Zone 2= intermediate
Zone 3= detox, can become hypoxic
What model is based on
- 1 central v
- 2 central v.
- 3 central v.
- Classical- flow of blood to central vein = ENDOCRINE F(X) of liver.
- acinus of rappaport (metabolic activity)
- portal lobule (flow of bile)= EXOCRINE
Flow of bile and blood?
opposite directions.
Bile is a ___ secretion
EXOCRINE
Bile canaliculi
Where bile is secreted. INTERcelllar space between apical surface of hepatocytes.
Flow of bile (start at hepatocyte)
Apical hepatocyte–> bile canaliculi –> canals of hering= bile ductule –>bile ducts –>hepatic (rt/left) duct –> common hepatic joins cystic duct –>common bile duct
Canal of hering
bile ductULE found at periphery of lobules
Bile contains?
cholesterol, phospholipids, bile salts, conjugated bilirubin and electrolytes
(so all these are excreted with bile)
Also IgA and drugs and heavy metals?