PBL 2- Liver, Bilirubin and Portal Hypertension Flashcards
What are the functions of the liver?
- Bile synthesis
- Glycogen Storage
- Clotting Factor Production
What are the two liver surfaces?
1) Diaphragmatic surface
2) Visceral Surface
Explain the Diaphragmatic surface
anterosuperior surface
- smooth and convex
- fits between the curvature of the diaphragm
- ‘bare area’ of the liver- posterior aspect of diaphragmatic surface not in contact with the diaphragm
Explain the Visceral surface
posteroinferior surface
- irregular and flat
- With exception of fossa of gall bladder and porta hepatis, it is covered with peritoneum
Describe the ligaments of the liver
1) Falciform Ligament (curved)- attaches the liver to the diaphragm. Division between the L and R lobes, Contains Ligamentum Teres (remnant of umbilical vein)
2) Coronary Ligament- Attaches superior surface of liver to inferior surface of diaphragm. Separates the bare area of the liver. Anterior and posterior folds unite to form the triangular ligaments on the R and L lobes
Lesser Omentum- attaches liver to the stomach
3) Hepatoduodenal Ligament- Extends from porta hepatis to duodenum
4) Hepatogastric Ligament- Extends from stomach to the liver
Describe the hepatic Recesses
anatomical spaces between the liver and surrounding structures
1) Subphrenic spaces- Divided into L and R by the falciform ligament
2) Subhepatic spaces- located between the inferior surface of the liver and the transverse colon
3) Morison’s pouch- potential space between visceral surface of liver and right kidney
Describe the lobes of the liver
The lobes are covered by a fibrous layer- Glisson’s capsule. Has a left, right, caudate and quadrate lobe
1) Caudate Lobe- lies between IVC and fossa produced by Ligamentum venosum
2) Quadrate Lobe- lies between gallbladder and fossa produced by ligamentum teres
look at pics
What separates the Caudate and quadrate lobes
Porta Hepatis- deep, transverse fissure
What are the liver cells called
Hepatocytes
How are hepatocytes arranged, their shape and what are they drained by.
Arranged into lobules Hexagonal shaped Drained by a central vein Regenerative ability Performs major metabolic functions
Describe a Hepatocyte
Hexagonal shaped
1) Has a portal triad at each corner of the hexagon.
Portal TRIAD contains:
- Portal Arteriole: branch of hepatic artery entering the liver
- Portal Venule: Branch of hepatic PORTAL vein entering the liver
- Bile duct: Branch of bile duct leaving the liver
2) Has a singular central vein in the middle of the hepatocyte (looks like a dot)
3) Sinusoids- run from central vein to the portal triads
* look at pics*
What are the acinar zones of the liver and describe them
Zone 1- Aerobic reactions, Respiratory chain, Krebs cycle, Fatty acid oxidation, production and bile secretion
Zone 2- ill defined intermediate area
Zone 3- Anaerobic reactions, Glycolysis, Glutamine synthesis and Xenobiotic metabolism
(zone 1 is closest to the portal triads and then zone 2 and zone 3) look at pics
What are Kupffer cells
Liver macrophage cells that line the walls of the sinusoids
Function- Phagocytosis
What are Hepatic stellate/ Perisinusodial cells
found in the space of Disse. Normally in quiescent phase and store Vitamin A.
However, when Liver is damaged- it is activated and it proliferates. it is responsible for secreting collagen scar tissue which causes cirrhosis.
Describe liver’s blood supply
DUAL blood supply
- Hepatic Artery (25%): supplies O2 to the non-parenchymal cells of the liver (kupffer and hepatic). derived from the coeliac trunk
- Hepatic Portal Vein (75%): Supplies liver with PARTIALLY deoxygenated blood, delivers to liver parenchyma (hepatocytes). Derived from the stomach, intestine and spleen.
- -> Hepatic vein drains into the IVC
