A: Compact bone tissue
B: Trabeculae of spongy bone tissue
C: Red bone marrow
Compact bone tissue
1: Haversian canal (=central canal),
2: Blood vessel,
3: Lacunae - the osteocytes are not seen,
4: Lacunae - the black dots inside the lacunae are the nuclei of the osteocytes,
5: Osteon (cross sectioned).
Spongy bone tissue
6: osteoblasts are the smaller cells on the surface
of the trabecula
7: osteocytesare prisonner inside the bone matrix (dark red material)
8: osteoclasts are the bigger cells on the surface
of the trabecula. They are multinucleated (= several nuclei / cell)
a: nuclei
The endosteum is made of all the osteoblasts (6) and osteoclasts (8) lining the surface of the trabeculae.