| 1. | Collagen fibres |
| 2. | Elastic fibres |
| 3. | Mesh of collagen and elastic fibres |
 | Collagen fibres |
 | Elastic fibres |
 | Mesh of collagen and elastic fibres |
|
It is not necessary to prepare ultra-thin sections for examinations under the scanning electron microscope because the electron beam does not penetrate the object, in contrast to transmission electron microscope (TEM).
The SEM image is created directly by a point-to-point visualization of the surface details of the specimen. To achieve this effect, a very thin electron beam scans the surface of the specimen line by line. Each surface point emits secondary electrons whose different intensities are measured by a detector.
When preparing tissue specimens for a scanning electron microscopic examination, the specimens are dried instead of embedded and sliced after fixation and dehydration.
The dehydration technique commonly used today is critical-point drying. The dried specimens are then coated with gold in a vacuum, the so-called sputtering apparatus. This covers the specimen with a surface which can emit secondary electrons.
| Vorkommen: | Haut, Knochen, Knorpel, Sehnen, Organkapseln, Basalmembran u.a. |
| Funktion: | große Zugfestigkeit, minimale Dehnbarkeit (hoher Elastizitätsmodul) |
| Vorkommen: | besonders zahlreich in der Lunge und in herznahen Arterien, ansonsten stets gemeinsam mit den kollagenen Fasern |
| Funktion: | große Dehnbarkeit (100 - 150%) bei völliger Rückkehr zur Ausgangslänge (geringer Elastizitätsmodul) |
Magnification:
3000x
Magnification:
10000x
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!