The cartilage extracellular matrix (ECM) is somewhat rigid and the chondrocytes are permanently located in small cavities of the ECM called lacunae.
Chondrocytes frequently undergo some shrinkage during fixation and the remaining process of preparing paraffin blocks for further sectioning. On the other hand the ECM suffers much less shrinkage.
The shrinkage of chondrocytes can be observed in tissue sections. As a result of the shrinkage of chondrocytes it is very frequent to see “empty”, unstained spaces, inside the lacunae.
There are many chondrocytes in the image. Identify them. When you place the cursor over the image, the cytoplasm and nucleus of some chondrocytes become highlighted in red and blue, respectively.
Many lacunae appear totally or partially empty, unoccupied by chondrocytes, due to the retraction of cells. Some of these spaces are highlighted in turquoise.
The extracellular matrix of cartilage stains blue or purplish after staining by hematoxylin and eosin. Observe that no connective tissue fibers are seen in the ECM.
The perichondrium that covers the cartilage is highlighted in green.
