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Effects of Mechanical Vibration on Bone Tissue
Published in Redha Taiar, Christiano Bittencourt Machado, Xavier Chiementin, Mario Bernardo-Filho, Whole Body Vibrations, 2019
Christiano Bittencourt Machado, Borja Sañudo, Christina Stark, Eckhard Schoenau
An important classification rises if we consider bone porosity degree (the volume fraction of soft tissue): the trabecular (cancellous) and compact (cortical) bone. Trabecular bone presents porosity degree ranging from 75% to 95%, showing an important metabolic role. It can be found in the ends of long bones (epiphysis), flat and cuboidal bones. Non-calcified regions are filled with marrow. Compact bone forms the bone cortex, its porosity ranging from 5% to 10%. It forms the shaft of long bones and the shell of cancellous bone. It is mainly responsible for mechanical functions and protection. Concentric lamellae are formed by a network of packed collagen fibrils which run in perpendicular planes in adjacent lamellae (also known as a plywood-like arrangement). The important Haversian canals (with 50 µm of diameter approximately), aligned to the long bones, containing nerves and blood vessels. These canals are connected by transverse Volkmann’s canals (Martin et al., 2010; Machado, 2013). Compact bone can still be classified as primary and secondary bones. Primary bone forms the osteon and the Haversian canals (circumferential lamellar bone), and it is mineralized tissue laid on the surface of bone. There is another type of primary bone, the plexiform bone, consisting of woven and lamellar bone producing a “brick wall” semblance. The secondary bone is produced by remodeling (secondary osteons appear under the primary bone).
Tissue Structure and Function
Published in Joseph W. Freeman, Debabrata Banerjee, Building Tissues, 2018
Joseph W. Freeman, Debabrata Banerjee
Lamallae consist of layers of mineralized collagen fibers that wrap around the Haversian canal (Figures 4.10 and 4.12). Layers range in thickness between 3 and 7 microns and are separated from each other by interlamellar layers. Osteons have diameters ranging from 200 to 300 microns. This central channel is called a Haversian canal, with a diameter of 50–90 microns. Within the Haversian canal is a blood vessel, typically 15 mm in diameter. Haversian canals contain nerve fibers and other bone cells called bone-lining cells. Bone-lining cells are actually osteoblasts, which have taken on a different shape following the period in which they have formed bone. If you cut a cross-section through a region of compact bone, you will see rings of Haversian systems, each with a hole, the canal, in the center. Cutting through the region of cancellous bone produces a more complex section because the systems have many different orientations.
An Overview of Human Bone, Biomaterials and Implant Manufacturing
Published in Pankaj Agarwal, Lokesh Bajpai, Chandra Pal Singh, Kapil Gupta, J. Paulo Davim, Manufacturing and Industrial Engineering, 2021
Pradeep Singh, Pankaj Agarwal, I.B. Singh, D.P. Mondal
The microstructures of cancellous and cortical bone are shown in Figure 9.1(b) and (c) respectively (Fyhrie and Kimura 1999). For cancellous bone, the volume fraction of hard tissue is very low as compared to cortical bone. The shape of the hard tissues is roughly cylindrical and are attached to one another to form interconnected cavities. These cavities host the bone marrow and provide passage for the circulation of biofluid. For cortical bone, the volume fraction of hard tissues is higher as compared to the cancellous bone. Haversian canals in the cortical bone are also long and close to cylindrical in shape. Blood vessels and nerves travel through the Haversian canal.
Simulation study on the effect of resistance exercise on the hydrodynamic microenvironment of osteocytes in microgravity
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Hai-Ying Liu, Chao-Hui Zhao, Hao Zhang, Wei Wang, Qing-Jian Liu
Bone is typically comprised of dense bone, cancellous bone, and tissue fluid. The osteon is the basic structural and physiological unit of dense bone, and it also has the highest bone density in the human skeletal system (Liu et al. 2020; Larcher and Scheiner 2021). The central tubular area of the osteon is called the Haversian canal, which contains arterial and venous capillaries that permit the transport of nutrients and metabolic waste needed for cell metabolism. The multi-layer circumferential lamellae around the Haversian canal consist of a complicated lacunar-canalicular system (LCS). The osteocytes are located in bone lacunae, and the adjacent osteocytes form a complex spatial mechanical signal transduction network through synaptic connections in the canaliculi. The LCS is an important channel for material exchange between osteocytes and capillaries in the Haversian canal (Kwon et al. 2010). The deformation of the bone matrix under loading can induce liquid flow in the LCS, and the mechanical signals produced by the liquid flow are perceived and responded to by osteocytes, thus regulating the activity of osteoblasts and osteoclasts to adjust bone mineral density to adapt to the current mechanical environment (Tovar et al. 2004).