Information
Drawing
Staining
Knowledge
marked
unmarked

Specimen Nr. 04B

Specimen:

Cerebrum (Human being)

Staining:

Weigert stain of myelin sheath

Magnification:

25x

Important structures :

1.Medulla, white matter
2.Cortex with some radially-oriented myelinated axons
Ausschnitt an der Grenze zwischen Mark und Rinde. Die Grenze wird immer unschärfer, je stärker man vergrößert, weil viele afferente (aufsteigende) Axone ihre Markscheide nicht an dieser Grenze verlieren, sondern erst kurz vor ihrer synaptischen Endigung. Entsprechendes gilt für die absteigenden (efferenten) Axone der Pyramidenzellen. Bei den hellen Löchern handelt es sich um Gefäßanschnitte.

Legende:

Medulla, white matter
Cortex with some radially-oriented myelinated axons

Myelin-sheath stains

Weigert iron-hematoxylin stain

Structures Colour
Nuclei black to blue-black
Cytoplasm -
Connective-tissue fibres
    - Collagen
    - Reticular
    - Elastic
-
-
black to blue-black
Myocytes black to blue-black
Erythrocytes black to blue-black

Dyes:

Iron-hematoxylin: is a hematoxylin and stains far more intensively than hemalaun. To be able to stain myelin sheaths with Weigert dye, the lipids in the myelin must be preserved while preparing the specimen. The myelin sheaths turn black to blue-black.
Luxol fast blue: Only the neurokeratin remains in normal paraffin fixation of myelin sheaths. Luxol fast blue has a specific affinity to this lipoprotein and stains the myelin sheaths bright blue.
Osmium tetroxide The specimens must be prepared as frozen sections. Osmium tetroxide is deposited on the double bonds of unsaturated fatty acids and produces reaction products which make even the thinnest myelin sheaths visible through black stain.
Die afferenten Axone der Großhirnrinde kommen entweder von subcorticalen Neuronen (Thalamus) oder es handelt sich um Axone von Pyramidenzellen in anderen Rindenfeldern (ipsi- oder kontralateral).

Home
Tutor
Help
Exit
Boxes

Magnification:

2x

Magnification:

25x

Magnification:

65x

Magnifications
Medulla, white matter
Cortex with some radially-oriented myelinated axons

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!

Cose help