liver rebecca nardi ran2101@columbia.edu. blood supply lab 19, slide 26 75% of blood supply from gut...

Liver

Rebecca Nardi

ran2101@columbia.edu

Blood Supply

Lab 19, Slide 26

•75% of blood supply from gut (Venous Portal system)

•25% from Hepatic Artery

•Blood flows from the Portal Triad to the Central Vein via Sinusoids

The Liver – A 3-D View

Lab 19, slide 25 http://www.biologymad.com/Kidneys/liverlobule.jpg

Portal Triad (+lymph!)

Portal Triad (+lymph!)

Lab 19, Slide 28

Cords (or Plates) and Sinusoids

Plates of Hepatocytes

Blood-filled Sinusoids

Space of DisseLab 19, Slide 30

Space of Disse

Microvilli

Endocytic Vacuole

•The Space of Disse is continuous with the lumen of the sinusoids due to spaces between the endothelial cells as well as in the basal lamina.

•This holds back cells, but not proteins. Proteins made in the liver can easily move into the blood.

Endothelium

Central Vein

Lab 19, Slide 29

Lymph

• Plasma that remains in the perisinusoidal space drains via lymphatics in the

OPPOSITE direction as blood – i.e. from hepatocytes to the triad, and finally to the

hilum.• 80% of the hepatic lymph drains into the

thoracic duct.

Three LobulesClassic Lobule

Portal Lobule

Liver Acinus

SHAPE Polygon (hexagon)

Triangle Ellipse (or diamond)

CENTRAL VEIN

Central 3 Tips 2 Tips (triads at

other tips)

Portal triads at corners

Follows bile

drainage

Reflects blood supply

Classic Lobule

Portal Lobule

Liver acinus

1 22 33

Bile•Made by hepatocytes – it is secreted into canaliculi between cells

•Hering canals connect canaliculi to bile ducts

•Moves in opposite direction from blood – towards the portal triad

•Nasty stuff – Canaliculi are bounded by tight junctions

Bile Canaliculi – Low Power

Phosphotungstic Acid & Hematoxylin stains the canaliculi.

Bile Canaliculi

Canaliculus in Cross-section

Space of Disse

Tight Junctions

Kupffer Cells•Macrophages, derived from monocytes.

•They form part of the lining of the sinusoid, but do not form junctions with endothelial cells.

http://medocs.ucdavis.edu/cha/402/PIX/1877/1877090.jpg

What is at the pointer?

Is it carrying blood/bile to/from hepatocytes?

Portal Vein

It is carrying blood to the hepatocytes.

Where is the highest O2 Content?

http://www.md.tsukuba.ac.jp/public/basic-med/anatomy/okado-group/Anatomy/C_description/c-1&2_liver/lobule.jpg

A B C

C – Zone 1 of the Acinus