The compact bone is an elongated cylindrical structure that forms the tough, outer layer of the majority of bones. Also referred to as the cortical bone, it provides a framework and strong support to the human body. It is heavy, tensile, dense, and primarily consists of calcium. Its strength and hardness can be judged from the fact that a saw is required to break the bone into pieces.Contradictory to its name, spongy bones are not soft. They are named so because they closely resemble a kitchen sponge. They are solid and hard, but when viewed under a microscope, are very similar to that of honeycomb. In short, these bones are porous, but that doesn't mean they can be squished like a sponge.
![Tissue Tissue](http://faculty.collin.edu/mweis/Images/Histology/2401%20histology/Tissue%20Histo/tissue%20histo%20labeled/tissues_histo_CT_BONE_GROUND_labeled.png)
Microscopic Study of Compact Bone. Preparation is one in which the the mineral has been removed, leaving behind the organic components of the tissue. Examining epithelial tissue under the microscope Information. Epithelial tissue serves two main functions in the body. It provides linings for external and internal surfaces that face harsh environments.The outer layer of the skin is epithelial tissue, as are the innermost layers of the digestive tract, the respiratory tract, and blood vessels.
Their porous nature helps to hold the bone marrow―soft tissue that produces red blood cells. The tiny spaces or cavities of the bone also hold the nerves and capillaries that exchange nutrients in and out of the spongy bone. When observing the compact bone under the microscope, it seems to have a tightly packed cell structure. A compact bone may appear like a solid, smooth structure, but when examined under a microscope, it is made up of canals (tubular pathways) that store the nerves and blood vessels.The compact bone primarily consists of star-shaped cells, referred to as osteocytes. These cells are stacked one above the other, encircling the canals.
The combined structure of osteocytes forming a ring-like pattern around the canals is referred to as osteons. An osteon, under the microscope, looks like a long cylindrical tube with the central section of the structure containing blood vessels, veins, and nerves. Osteons together look like a bundle of straws that are oriented in the same direction.The spongy bone is made up of trabeculae―microscopic pillar-shaped units that form a mesh-like network of connective tissue. Unlike the compact bone that forms a well-organized pattern of osteons, the spongy bone has a lamellar or layered pattern, meaning it forms a sheet-like mass of connective tissue. It is an interconnected network of flat pieces of bone with open spaces that are occupied by the bone marrow.