Why is this image of bone section? – observe a homogeneous acidophilic region (pink after HE), cells lining the bone trabecula, and cells within the trabecula.
Main components of this image: a) a segment of a bone trabecula; b) loose connective tissue surrounding the trabecula; c) two blood vessels within the loose connective tissue (in orange after using the mouse).
There are two lineages of cells in bone tissue: the osteoblastic lineage and the osteoclastic lineage.
The osteoblastic lineage is composed of three cell types: osteoprogenitor cells, osteoblasts, and osteocytes. Osteoblasts and osteocytes are easily recognizable in histological sections, but not the osteoprogenitor cells.
The osteoclasts result from the fusion of cells of the monocyte precursors.
In the lower figure observe the location of some of the bone cells:
1 – Osteoblasts (in orange after clicking) are apposed on the outer surfaces of a bone. They constitute the majority of the cells covering the bone matrix and resemble an epithelium.
2 – Osteocytes are cells located inside the bone, surrounded by extracellular matrix. They are highlighted in green. Two osteocytes (highlighted in dark green) are very close to the surface of the trabecula and possibly are two osteocytes that recently be came surrounded by bone matrix, transitioning from osteoblast to osteocyte.
3 – Observe an osteoclast on the outer surface of a trabecula, (highlighted in dark blue).It is a very large cell with a darker stained cytoplasm. It is multinucleated: three or four nuclei can be seen in this section
Bone trabecula. Staining: HE. Magnification: medium.
Cells of the bone. Staining: HE. Magnification: medium.