Specimen Nr. 06

Specimen:

Proximal tubular cells, kidney (Mouse)

Staining:

TEM

Magnification:

18000x

Important structures :

1.	Nucleus of proximal tubular cell
2.	Microvilli (brush border)
3.	Pinocytotic vesicles
4.	Terminal bar (Zonula occludens and zonula adherens)
5.	Cell membrane - folds (basal cell pole)
6.	Mitochondria
7.	Lysosome
8.	Lumen of peritubular capillary
9.	Fenestrated endothelium of capillary vessel
10.	Basement membrane

Die Abbildung zeigt die Anschnitte zweier Zellen eines proximalen Tubulus convolutus, deren Längsachse im Bild diagonal ausgerichtet ist. Am apikalen Zellpol sind zahlreiche Mikrovilli (lichtmikroskopisch Bürstensaum!), tubuläre Plasmalemmeinfaltungen, aus denen sich pinozytotische Vesikel abschnüren und eine Schlussleiste zu sehen. Basal liegen tiefe Einfaltungen des Plasmalemms, zwischen denen zahlreiche Mitochondrien liegen. Eine Kapillare mit gefenstertem Endothel und einer dicken Basalmembran grenzt basal an die Tubuluszelle.

Legende:

	Nucleus of proximal tubular cell
	Microvilli (brush border)
	Pinocytotic vesicles
	Terminal bar (Zonula occludens and zonula adherens)
	Cell membrane - folds (basal cell pole)
	Mitochondria
	Lysosome
	Lumen of peritubular capillary
	Fenestrated endothelium of capillary vessel
	Basement membrane

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.

Die pinozytotischen Vesikel und Lysosomen dienen der Rückresorption und proteolytischen Verarbeitung der rückresorbierten Proteine (vgl. das Präparat von der Ratte, der Trypanblau in die Blutbahn injiziert wurde). Die enge Beziehung der Mitochondrien zu den Einfaltungen des basalen Plasmalemms ist wichtig für den energieverbrauchenden Ionentransport gegen ein Konzentrationsgefälle.

Nucleus of proximal tubular cell

Microvilli (brush border)

Pinocytotic vesicles

Terminal bar (Zonula occludens and zonula adherens)

Cell membrane - folds (basal cell pole)

Mitochondria

Lysosome

Lumen of peritubular capillary

Fenestrated endothelium of capillary vessel

Basement membrane

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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