What are osteons in bone?
Osteons are cylindrical vascular tunnels formed by an osteoclast-rich tissue. They contain pluripotential precursor cells and endosteum known as the cutting cone. The bone removed by the cutting cone is replaced by osteoblast-rich tissue.
How are collagen fibers oriented?
The collagen fiber orientation in the osteonal bone is generally categorized in three groups: dominantly transverse, dominantly longitudinal, and a combination of transverse and longitudinal orientations.
Where are trabeculae located?
Trabecular bone, also called cancellous bone, is porous bone composed of trabeculated bone tissue. It can be found at the ends of long bones like the femur, where the bone is actually not solid but is full of holes connected by thin rods and plates of bone tissue.
Where are osteons located?
Compact Bone
Compact Bone The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix. Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae.
What is the difference between osteons and osteocytes?
Definition. Osteons refer to the chief structural unit of a compact bone, consisting of lamellae and Haversian canals. But, osteocytes refer to the bone cells formed when and osteoblasts become embedded in the material it has secreted.
Why is the orientation of the fibers important for the function of the tissue?
In dense irregular connective tissue, the direction of fibers is random. This arrangement gives the tissue greater strength in all directions and less strength in one particular direction.
Why is osteons laid out parallel?
Cylindrical structures, called osteons, are aligned along lines of the greatest stress to the bone in order to resist bending or fracturing.
Where are the osteons?
Compact bone
Compact bone consists of closely packed osteons or haversian systems. The osteon consists of a central canal called the osteonic (haversian) canal, which is surrounded by concentric rings (lamellae) of matrix. Between the rings of matrix, the bone cells (osteocytes) are located in spaces called lacunae.
What is Fibre orientation?
Fiber orientation refers to the optimal structural arrangement of individual fibers in the development and manufacture of advanced composite materials (ACM) and fiber-reinforced composites (FRC). Most ACMs and FCMs are made from two main constituents: matrices and reinforcements.
What is the effect of Fibre orientation on material properties?
This concept was the inspiration to design similar man made composites and to study the effect of fibre orientation in a systematic experimental investigation. In general, fibre-reinforced plastics show enhanced properties such as low weight, corrosion resistance, and high tensile strength and modulus.
What is collagen and its function?
Collagen is protein molecules made up of amino acids. It provides structural support to the extracellular space of connective tissues. Due to its rigidity and resistance to stretching, it is the perfect matrix for skin, tendons, bones, and ligaments.
What is the boundary of an osteon?
Each osteon consists of concentric layers, or lamellae, of compact bone tissue that surround a central canal, the haversian canal. The haversian canal contains the bone’s blood supplies. The boundary of an osteon is the cement line .
What is the osteon system?
The osteon or haversian system / həˈvɜːr.ʒən / (named for Clopton Havers) is the fundamental functional unit of much compact bone. Osteons are roughly cylindrical structures that are typically several millimeters long and around 0.2 mm in diameter. They are present in many bones of most mammals and some bird, reptile, and amphibian species.
What are the characteristics of primary osteons?
Primary osteons are the first to be laid down in early life, that is, where bone did not exist previously, and are relatively small structures. During postnatal growth, new woven bone forms in the periosteum of long bones and is transformed into new primary osteons ( Figure 13-14 ).
What is the diameter of an osteon?
An osteon is a few millimeters in length and has a diameter of approximately 0.2 mm [31, 32]. Starting from the outside of the osteon and moving inward, the osteon is rimmed by the cement line, a band of less stiff material with an important role in resisting fracture [33].