Das Bild zeigt mehrere Schilddrüsenfollikel, deren Lichtung von Kolloid ausgefüllt ist. Die Zellen des einschichtigen platten bzw. einschichtigen isoprismatischen Epithels, das die Wände auskleidet, weisen länglich-ovale bzw. runde Zellkerne auf. Die einzelnen Follikel sind durch lockeres faseriges Bindegewebe mit zahlreichen Fibrozyten und Kapillaren voneinander abgegrenzt. Vereinzelt sind C-Zellen (parafollikuläre Zellen) zu sehen.

Legende:

	Simple cuboidal epithelium with round cell nuclei
	Simple squamous epithelium with elongated oval cell nuclei
	Loose fibrous connective tissue with fibrocytes and capillary vessel
	C-cell (parafollicular cell)

Hematoxylin and Eosin (H&E)

H&E is the most common survey stain, which shows cell nuclei and cytoplasmatic components.

Structures	Colour
Nuclei	blue
Cytoplasm	pale red
Connective-tissue fibres - Collagen - Reticular - Elastic	red - pale rose to red
Muscle tissue	red
Erythrocytes	red-orange

Dyes:

Hematoxylin

(e.g. hemalaun, Weigerts or Heidenhains iron-hematoxylin)
Hematoxylin is a positively charged dye (at low pH values). It therefore colors negatively charged (basophilic) structures blue, like the DNA of nuclear chromatin, the RNA of rough endoplasmatic reticulum, and the acidic glycosaminoglycans of hyaline cartilage.
Hematoxylin used in the preparation of iron varnish is Weigerts or Heidenhains iron-hematoxylin and in the preparation of aluminum varnish is hemalaun.

Eosin

Eosin is a negatively charged dye used for counterstaining. It stains all remaining structures different shades of red (acidophilic).

Thiazinrot

Thiazinrot behaves similar as eosin.

Die sekretorische Tätigkeit der Follikelepithelzellen steht unter der Kontrolle des TSH (Thyreoideastimulierendes Hormon) aus dem Hypophysenvorderlappen. Der Hypophysenvorderlappen wird durch TRH (Thyreotropin-releasing Hormon) des Hypothalamus stimuliert. Ein niedriger Schilddrüsenhormonspiegel induziert die Bildung von TRH, ein hoher hingegen wirkt bremsend auf die sekretorische Tätigkeit der thyreotropen Zellen des Hypothalamus (negative Rückkopplung).

Simple cuboidal epithelium with round cell nuclei

Simple squamous epithelium with elongated oval cell nuclei

Loose fibrous connective tissue with fibrocytes and capillary vessel

C-cell (parafollicular cell)

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. 01C

Specimen:

Staining:

Magnification:

Important structures :

Legende:

Hematoxylin and Eosin (H&E)

Dyes:

HistoNet2000 - Help