Specimen Nr. 05

Specimen:

Hepatocyte (Mouse)

Staining:

TEM

Magnification:

26000x

Important structures :

1.	Endothelium of liver sinusoid
2.	Bile capillary
3.	Space of Disse (perisinusoidal space) with microvilli of 2 hepatocytes
4.	Tight junction
5.	Nucleus of hepatocyte
6.	Mitochondrion
7.	Golgi apparatus
8.	Lysosome
9.	Lipoid droplet
10.	Smooth endoplasmatic reticulum
11.	Rough endoplasmatic reticulum
12.	Glycogen particles

Das Bild zeigt Details von einem Ausschnitt eines Leberzellbälkchens. Der extrazelluläre Raum zwischen dem Lumen des Lebersinusoids und der Gallenkapillare ist zum Disse´schen Raum erweitert. Gegen die Gallenkapillare ist er durch "tight junctions" abgedichtet. Das Endothel des Sinusoids ist gefenstert. Die Oberfläche der beiden Leberzellen ist durch Mikrovilli vergrößert. Im Zytoplasma der beiden Leberzellen sind zahlreiche Zellorganellen, wie rauhes und glattes endoplasmatisches Retikulum, Golgi-Komplex, Mitochondrien und Lysosomen zu erkennen. Auf die Speicherfähigkeit der Leberzelle weisen die paraplasmatischen Substanzen hin, die in Form von Lipoidtropfen und Glykogenpartikeln vorliegen.

Legende:

	Endothelium of liver sinusoid
	Bile capillary
	Space of Disse (perisinusoidal space) with microvilli of 2 hepatocytes
	Tight junction
	Nucleus of hepatocyte
	Mitochondrion
	Golgi apparatus
	Lysosome
	Lipoid droplet
	Smooth endoplasmatic reticulum
	Rough endoplasmatic reticulum
	Glycogen particles

Transmission electron microscope (TEM)

The sections for examination under the transmission electron microscope are about 0.1µm thick. They are referred to as ultra-thin sections.

To obtain such ultra-thin sections, the tissues are embedded in plastic polymers like epon (instead of paraffin, which is used for examination under the light microscope) after fixation and dehydration. Ultra-thin sections are not stained with dyes, but contrasted with heavy-metal salts. The heavy-metal salts lead to a different electron scatter and thereby create a differentiated blackening of the photographic negative. A common method of creating contrast results with 5% uranyl acetate and lead citrate.

HistoNet2000 - Help

1. Organization of the screen surface

Right side: histologic specimen
Left side: information about the specimen (above) and general program functions (below)

2.Histologic specimen

Pull the mouse across the histologic specimen for training purposes. A small square with exclamation marks (dynamic labels) will appear where there is an important structure. You should then decide what structure this could be. To check your result, simply click the appropriate square, and the correct label will appear. The option “marked” allows you to see all labels for all structures simultaneously. These can be removed by clicking “unmarked”. This reactivates the dynamic labels.

3. Complementary information

Info: general information about the specimen, as well as a list of the dynamic labels
Drawing: schematic drawing of the specimen
Staining: information about the staining method for this specimen
Knowledge: short texts with basic histologic information, presently deactivated

4. General Program Functions

Home: returns you to the “start” page
Tutor: how to contact the HistoNet Team
Help: Instructions for Use appear
Exit: closes down the HistoNet program
Boxes: goes back to the other specimen of a topic
VM: provides virtual microscopy

We hope you will enjoy working with HistoNet2000 and learn a lot from it!