Section of a liver in low magnification

CV

Portal triad

CV= Central vein

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Section of a liverMZI Khan

This section of a liver is showing many hepatic lobules centered around central vein.

Interlobular connective tissue is not present here, therefore, demarcation of lobules from one another is difficult here.

Portal Triad

Section of a Pig LiverMZI Khan

Section of this liver is Showing:

Benzene-shaped hexagonal hepatic lobules, which are demarcated by connective tissue.

Central vein at the center of lobule.

Portal areas at the angle of lobules.

Section of LiverMZI Khan

Section showing central vein, sinusoids, and hepatic cords.

Hepatic cords consisting of six sided liver cells (hepatocytes).

The hepatocytes seems to be radiating from the central vein towards periphery of the hepatic lobule.

Sinusoids are the open channel of blood in between the hepatocytes.

Section of a liver showing a lobule and surfaces of the hepatocytes

Surfaces of hepatocytes:

(1)Microvillus surfaces that face the perisinusoidal space,

(2) Surface that border the bile canaliculi, and

(3) Contact surface between adjacent hepatocytes where apposed surface (lateral face).

The hepatocytes have centrally located spherical nucleus with one or more prominent nucleoli. Occasionally binucleated cells may see

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Portal areas/canal/triads of liverMZI Khan

Portal triads have:

(1) Hepatic artery

(2) Portal vein, and

(3) Bile duct

Classification of hepatic lobules MZI Khan

Classical hepatic lobule

Portal lobule Liver acinus

Diagrammatic representation of Classical liver lobule

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Composition of a lobule already discussedIn the previous slides.

The Portal Lobule of liver

Portal lobule is a functional unit centered around the bile ductule in the portal area. It is defined as a triangular area consisting of the parenchyma of three adjacent hepatic lobules that are drained by the bile ductule in the portal canal.

Liver acinus

Liver acinus is a unit of parenchymadefined in relation to its vascular supply. The liver acinus is a roughly diamond shaped area made of parts of two hepaticlobules supplied by terminal branches of the interlobular portal vein and hepaticartery. The blood vessels course at rightangles from the portal area between twohepatic lobules to form backbone of theacinus, and the two central veins are atthe two opposing points of the diamond.The liver acinus is divided into threeZones: zone1, 2, and 3.

Diagrammatic representation showing lining cell of the sinusoids and space of Disse

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Lining cells of the sinusoids are:

(1) Porous endothelial cell

(2) Von Kupffer cell: Macrophage, &

(3) Perisinusoidal stellate cells or adipocyte, or Ito cell, which store vitamin A.

Space of Disse is the space in between endothelium of the sinusoids and hepato -cytes. Here the exchange of the metabolites takes place.

Basic structure of Liver Lobule showing Flow of Blood and Bile

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Basic Structure of Liver Lobule Showing Flow of Blood and Bile

Flow of blood and bile in the hepaticLobule is opposite in direction