Page 275 - Atlas of Histology with Functional Correlations

FIGURE 7.23 ■ Bone formation: primitive bone marrow and development of
osteons (Haversian systems; decalcified bone, transverse section). Stain:

hematoxylin and eosin. Medium magnification.

FIGURE 7.24 | Intramembranous Ossification:

Developing Mandible (Decalcified Bone,

Transverse Section)

This illustration depicts a section of mandible in the process of intramembranous

ossification. External to the developing bone is the stratified squamous
keratinized epithelium of the skin (1). Inferior to the skin (1), the embryonic
mesenchyme has differentiated into the highly vascular primitive connective
tissue (2) with nerves and blood vessels (9) and a denser periosteum (3, 10).

Below the periosteum (3, 10) is the developing bone. The cells in the
periosteum (3, 10) have differentiated into osteoblasts (6, 10) and formed
anastomosing bone trabeculae (7, 11) that surround the primitive marrow
cavities (8, 15). In the marrow cavities (8, 15) are embryonic connective tissue
cells and fibers, blood vessels (4), arterioles (12), and nerves. Peripherally,

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