Module: gastro intestinal system Histology of the major...

Jeanne Adiwinata pawitan - Bagian Histologi FKUI1

Module: gastro intestinal systemHistology of the major glands: The liver - 2008

Jeanne Adiwinata PawitanDept. of Histology FMUI


Major glands of the digestive system

They end up in the digestive tract:• Liver • Pancreas

• Gall bladder (Vesica fellea) – not a gland


Liver • inferior surface – transverse fissure =

porta hepatis° Portal vein° Hepatic a.° Ductus hepaticus (bile duct)

• Fibrous capsule = Glisson’s capsule° Septa → lobes → lobules° Certain region - peritoneum


Liver – microscopic structure• Cells → plates/sheets (1-2

cells thick) – branching –anastomosing

• Sheets – radial towards central vein –hexagonal prism/cylinder ≅ classical liver lobules

• Between sheets – sinusoids - blood → structure – endocrine gland

• Prism – corner – portal tract = portal canal = portal area = ∆ Kiernan


Portal tract• Connective tissue– contains branches of

° Portal vein° Hepatic artery° Ductus biliaris (bile duct)° Lymph vessel

• around portal tract - liver cells ( < the cells at the center) – 1 layer – limiting plate –pierced by branches of hepatic a., portal v., ductus biliaris


Units in the liver

• Classical lobule (lobulus hepatis)° Anatomical point of view ° Polyhedral

prism/cylinder, axis – central vein, portal tract - corners

• Portal lobule • Hepatic (liver) acinus


Portal lobule

• Triangular prism, axis – portal tract, central vein - corners.

• One portal lobule contains parts of 3 adjacent classical lobule

• Physiology: bile production – flow direction: to branches of ductus biliaris in portal tract


Liver acinus – portal acinus of Rappaport

• Irregular, ovoid-diamond shape, central vein – both ends, axis: connective tissue (periphery-classical lobule) – interlobular a. and vein (branches of the blood vessels in portal tract)

• Physiology: smallest unit of blood supply


Parenchyma – liver cells (hepatocytes)

• cell - polygonal – 20-35 µm° Surface ≥ 6° Nucleus 1, sometimes 2

(25%)• Size – highly variable• Round/ovoid – vesicular –

chromatin granules: few - distinct - scattered

• nucleolus 1/more - prominent

° Cytoplasm - variable ≅ functional activity

• glycogen/fat storage – routine HE – dissolved – irregular empty spaces (glycogen), round vacuoles (fat)


Liver cells (hepatocytes)• Cytoplasm ° Mitochondria: small

– numerous° Golgi apparatus

• Adjacent to nucleus• Periphery • Adjacent to canaliculi

biliaris (bile canaliculi)

° Clumps of basophilic materials → sometimes – cytoplasm - basophilic

• Cell membrane - distinct


Liver cell membraneLiver cell membrane is facing• Sinusoid

° Liver cell membrane – sinusoid → space of Disse (perisinusoidal space)

° Liver cell membrane – facing the space of Disse → microvilli

• Surface of another liver cell → irregular surface, sometimes–spot desmosome, tight j.→

• Canaliculi biliaris (bile canaliculi) - ∅ 1-2 µ m


Liver (hepatic)sinusoid∀ ≠ blood capillary - ∅

bigger → 9-12 µm• Lining cells ≠

ordinary endothelium° Endothelial cell,

sinusoidal lining cells° Phagocyte (stellate,

Kupffer) cells° (Intermediate cells)

• Basal lamina in continuous


Endothelial cells – sinusoidal lining cells

• Nucleus – small - flattened – dark• Cytoplasm - thin, overlapping – ME

° Thin part – pores ∅ ± 100 nm, diaphragm (-) → ≈ sieve

° In the cytoplasm• << small organelles• >> pinocytotic vesicles


Phagocyte (stellate, Kupffer) cells• Active - phagocytic • Number can ↑ - origin? diff –endothelial cells

(more primitive)• Nucleus – larger, pale• Cytoplasm

° > abundant, branching, traversing the sinusoid° Often contain

• Degenerated - erythrocytes • Iron containing - pigment granules


Perisinusoidal space (space of Disse)• Borders of perisinusoidal

space° Liver cell membrane

• Long microvilli –increase the surface for absorption, secretion

• Cytoplasm beneath the membrane – vacuoles, vesicles

° Sinusoidal wall (basal lamina, endothelial cells)

• Equivalent to interstitial space° Contains reticular,

collagen fiber° Fluid circulates freely


Perisinusoidal space (space of Disse)• Contains

° Mesenchymal cells = pericytes = fat storing (Ito) cell = lipocytes = extra vascular reticular cells

• Located near reticular/collagen fiber• Is believed to: form the fiber, store vitamin A• Might have a role in lymph production

° Pit cells = NK cells?• Sinusoidal wall ≠ barrier

° Basal lamina - in continuous° Endothelial cells - in continuous° → blood plasma (sinusoid) – perisinusoidal space –

liver cells → metabolite exchange: blood – liver cells


Bile flow – in the liver• Bile canaliculi

° Liver cell membrane • Ductulus (canal) of Hering

° Small-clear cells, on basal lamina, nucleus-dark, incomplete organelles

• Bile duct in portal tract° Small duct – simple cuboidal epithelium° Large duct – columnar epithelium, outside –

connective tissue• (Hepatic duct)


Blood flow in the liverPortal vein (75%), hepatic a. (25%) – porta hepatisBranches of portal v., hepatic a. – portal tract

Interlobular v., interlobular a.Inlet v., inlet a.Liver sinusoid

↓ central veinSublobular veinCollecting vein Hepatic vein → v. cava inferior


The end

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Module: gastro intestinal system Histology of the major...

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