Specimen Nr. 04

Specimen:

Fibroblasts of scar tissue (Sheep)

Staining:

TEM

Magnification:

9200x

Important structures :

1.Cell process
2.Nucleus
3.Nucleolus
4.Rough endoplasmatic reticulum
5.Secretory granule
6.Extracellular matrix

Der spindelförmige Zelleib der Fibroblasten zeigt lange verzweigte Zellfortsätze. Der der Zellform angepaßte Zellkern (Nucleus) weist ein Kernkörperchen (Nucleolus) auf. Im Zytoplasma sind vor allem die zahlreichen Zisternen des rauhen endoplasmatischen Retikulum mit hellem Inhalt und Sekretgranula gut zu erkennen. In der Umgebung des Fibroblasten befindet sich die extrazelluläre Matrix, die sich aus kollagenen Fibrillen und Proteoglykanen zusammensetzt.

Legende:

Cell process
Nucleus
Nucleolus
Rough endoplasmatic reticulum
Secretory granule
Extracellular matrix

Fibroblast[kr]

1. Rough endoplasmatic reticulum
2. Golgi apparatus
3. Secretory granule
4. Nucleus
5. Mitochondrion

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.

Das rauhe endoplasmatische Retikulum und der Golgi-Komplex sind die Zellorganellen, die eng mit der Synthese und Sekretion der extrazellulären Matrix zusammenhängen. In ihnen werden die Vorläufer der faserigen Bausteine (kollagene, elastische und retikuläre Faser) sowie die Grundsubstanz (Glykosaminoglykane und Proteoglykane) gebildet, "eingepackt" und an die Zellmembran transportiert. Mitochondrien liefern die nötige Energie für diese Vorgänge.

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Cell process
Nucleus
Nucleolus
Rough endoplasmatic reticulum
Secretory granule
Extracellular matrix

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

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