Diese Chondrozyten stammen aus tieferen Knorpelzonen des Gelenkknorpels. Sie erscheinen mehr oder weniger kugelig und weisen große Zellkerne, oft mit mehreren Nucleoli, auf. Die an den Zellkern grenzenden helleren Zytoplasmaareale sind der Golgi-Komplex, die dunklen, oft peripher gelegenen, Glykogeneinlagerungen. Unmittelbar an die Chondrozyten grenzend färbt sich ein schmaler Martixsaum, der Knorpelhof, intensiver an als die übrige extrazelluläre Matrix.

Legende:

	Chondrocyte
	Isogenous group of 2 chondrocytes
	Pericellular matrix
	Interterritorial matrix
	Golgi apparatus
	Glycogen granules

Semi-thin section

For semi-thin sections, the tissue is not embedded in paraffin (as is otherwise common for light microscopy), but in acrylic or epoxy resins, which are harder embedding substances, and permit thinner slices, so-called semi-thin slices of about 0.5 – max. 2µm in thickness, to be produced. After embedding in paraffin, a section is > 3µm thick. Semi-thin sections have better resolution under a light microscope than the thicker paraffin sections.

Embedding in epoxy resins is always performed when tissues are to be examined under a transmission electron microscope (TEM). Semi-thin sections are used to study the specimen under the light microscope before being examined under the transmission electron microscope (TEM).

Toluidine blue is primarily used to stain semi-thin sections since most dyes do not sufficiently infiltrate the epoxy resin. Toluidine blue stains various biologic components to different shades of blue.

Im Gelenkknorpel fehlen Gefäße und Nerven. Seine Ernährung erfolgt durch Diffusion, wobei der Stoffaustausch über die Synovia (Gelenkschmiere) stattfindet. Da der Gelenkknorpel keinen Überzug von Perichondrium besitzt, fehlt ihm die Regenerationsfähigkeit. Gelenkknorpel, insbesondere der des Hüft- und Kniegelenks, ist häufig von Zerstörung betroffen. Die nicht entzündliche Zerstörung von Gelenkknorpel wird als Arthrose, die entzündliche als Arthritis bezeichnet.

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!

Specimen Nr. 02

Specimen:

Staining:

Magnification:

Important structures :

Legende:

Semi-thin section

HistoNet2000 - Help