Bones are rigid and dynamic biological organs where a series of active cells resident and integrate into a stiff matrix and this structure physically support and protect the tissue and organs within our body. Bone stores minerals and bone marrow within bone structure produces new blood cells. over 270 pieces of bones are in infants’ body and several of them fuse together during growth. These bones are in different shapes and have complex and hierarchical structures. With different shapes, mechanical properties and biological activities, they act in a variety of roles for our body functions. In this review paper, we mainly focus on long bone healing, regeneration and tissue engineering strategies. A series of mechanisms such as biochemical mechanisms, cellular biology of bones, hormonal and pathological mechanisms have assignable effect on healing progress of bone tissue.
Osteoblasts, osteoclasts and osteocytes are three major bone tissue regeneration related cells that contributes to the completion of injury healing. Differentiated from Mesenchymal stem cells (MSCs), the major function of osteoblasts is to build bone extracellular matrix (ECM), known as osteoid, by producing and secreting organic compounds, such as Type I collagen. Osteoblasts are also involved in mineralization, where osteoblasts secret alkaline phosphatase that modify the phosphate groups to be the mineral deposition foci [1]. During bone formation, osteoblasts have two pathways to follow. One of these two is to become trapped in the matrix secreted by osteoblast itself and differentiate into osteocytes and the other is to undergo a programmed cell death, termed apoptosis [2]. Osteoblasts affect the skeletal architecture in two major aspects: bone matrix depo...
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However some of the basic bone functions include storing of crucial nutrients, minerals and lipids, producing red blood cells for the body, protect the organs such as heart, ribs and the brain, aide in movement and also to act as a buffer for pH. With the differences in all of the bones there are four things that remain the same in each bone, their cells. Bones are made up of four different cells; osteoblasts, osteoclasts, osteocytes and bone lining cells. Osteoblasts produce and secrete matrix proteins and then transport the minerals into the matrix. Osteoclasts are responsible for the breaking down of tissue. The osteoblasts and osteoclasts are both responsible for remodeling and rebuilding of bones as we grow and age. The production of osteoclasts for resorption is initiated by the hormone, the parathyroid hormone. Osteocytes are the mature versions of osteoblasts because they are trapped in the bone matrix they produced. The osteocytes that are trapped continue making bone to help with strength and the health of the bone matrix. The bone lining cells are found in the inactive bone surfaces which are typically found in
An osteoblast is a “baby” bone cell whose main job is to secrete osteoid which forms the hardened, or calcified, bone matrix. Osteocytes are formed from osteoblasts. Osteocytes are the mature bones cells that have been completely differentiated. They are found in the lacunae of hard bone and have a spider-like appearance due to their canaliculi. Osteoclasts are a different type of cell formed from the mesenchymal cells. These cells are not related to osteoblasts or osteocytes. Their job is to basically “eat” the bone to create cavities and other hallow spaces during bone remodeling. Finally, the cells form differentiate to form fibroblasts and fibrocytes. These fibroblasts and fibrocytes secrete and form the matrix for fibrous connective tissue which is an essential component of the
Bones are dense and provide support and structure to the body. The two types of bones is compact and spongy bones. Compact bones are dense and tough. Spongy bones are not as dense and are flexable. Bone remodeling occurs n 120-day cycles. Over the first 20 days resorption by osteoclasts occurs. Osteoclasts release proteases, clears away damaged bone, and releases matrix-bound growth factors. Bone formation occurs by osteoblasts over the last 100 days. Osteoblasts fill in bone cavity with bone matrix.
Eccentric axial loading of talus on calcaneus produces a primary shear line that is parallel to posterolateral edge of talus and passes through posterior calcaneal facet. This primary fracture line separates the calcaneum in to two parts viz posterolateral and anteromedial (fig 5.1). Each fragment consists of a portion of posterior facet. The amount of posterior
Bone contains an inorganic component composed of mineral salts, primarily calcium and potassium, and an organic component made of collagen, a complex protein that is found in various forms in bone and other connective tissues. According to Wolff’s Law, bone is capable of adjusting its strength in proportion to the amount of stress placed on it. When young, healthy people participate in exercise programs for extended periods of time, their bones can become more dense through increased deposition of mineral salts and the number of collagen fibers. On the other hand, if bones are not subjected to mechanical stresses, as in individuals with sedentary lifestyle or
New cells are often produced in the body during growth and development. In addition, new cells also develop as the body repairs and remodels its tissues after an injury. These new cells come from mesenchymal stem cells (MSCs), which are considered as multipotent cells. MSCs are found in various parts of the body during growth and development, but in adults, they are present in the bone marrow, where they later differentiate, mature and migrate to become more specialized cells with unique functions. These cells' potential to develop into bone cells, cartilage cells, muscle cells and fat cells makes their role in regeneration, repair and remodelling important, especially when the body undergoes the normal process of aging or recovers from disease or injury.
Bones of the skeletal system serve as storage compartments for vital minerals like phosphorus and calcium. Excessive calcium in the blood is stored in bones. Calcium is released from the bones into the blood when there are deficient amounts of it in the blood.
To protect different sections of the body there are 5 types of bones that serve a specific function for the system. The first type is long bone. Long bones are hard bones that provide strength, structure and mobility. (Medicine Net) These bones are longer than they are wide and they are mainly located in the appendicular skeleton. They also consist of several sections which are Diaphysis, epiphysis, metaphysic, and epiphyseal plates. The diaphysis is the long central shaft. Next, Epiphysis forms into the large ends of long bones while the area between the diaphysis and epiphysis is also known as metaphysis. Lastly, epiphyseal plates are plates of cartilage that allow growth to take place during childhood years. Cartilage cell production stops when the human body stops growing and the plates eventually become replaced by bone. Flat
Osteoporosis is a condition, which advances with age, resulting in fragile, weak bones due to a decrease in bone mass. Externally osteoporotic bone is shaped like normal bone, however it’s internal appearance differs. Internally the bone becomes porous due to a loss in essential minerals, including phosphate and calcium. The minerals are loss more quickly than they can be replaced and in turn cause the bones to become less dense and weak. The bones become prone to fracture, due to their weakness. Therefore the awareness of the disease tends to occur after a fracture has been sustained. The bones most commonly affected are the ribs, wrist, pelvis and the vertebrae.
Osteoporosis is a serious disease that leads to a faster than normal loss of the bone density, which puts the bone at a higher risk for fractures. In order to understand the causes of Osteoporosis, it is important to understand how bones are formed. Bone is a living tissue that is made mainly of collagen, calcium phosphate, and calcium carbonate. The mixture of collagen and calcium gives the bone strength and flexibility. The body deposits new bones and removes old ones; moreover, there are two types of bone cells that control the reproduction of bones. Cells called osteoclasts breakdown bone tissues thus, damaging the bone. Once the damaged bone is removed, cells called osteoblasts, use minerals including calcium and phosphate from the blood stream to make new healthy bone tissues. In order for osteoblasts and osteoclasts to work properly, hormones such us thyroid, estrogen, testosterone, and growth hormones are
Hoffmeister, Ellen. "Gene Therapy and Pharmaceuticals Offer Hope for Many Patients With Brittle Bones." Bone and Joint 11.5 (2005): 49-51. eBook.
Bone tissue engineering (BTE) plays an important role in treating bone diseases related to osteoporosis and other orthopedic treatments. Although several methods are used in orthopedic surgery, some bone transport methods such as autografting and allografting have a certain number of disadvantages. Both are expensive methods and they can be exposed to infections and diseases. Therefore, in stead of using these potential risky methods, bone tissue engineering process are used to treat in orthopedic treatments. In general, both tissue engineering and bone tissue engineering have major constituents including stem cells, scaffold, bioreactors and growth factors.
Describe the microscopic features of osseous tissue that help long bones withstand compressive forces without breaking.
Norvell, J. G. (2013, June 11). Tibia and Fibula Fracture Clinical Presentation. Retrieved from http://emedicine.medscape.com/article/826304-clinical
The field of regenerative medicine encompasses numerous strategies, including the use of materials and de novo generated cells, as well as various combinations thereof, to take the place of missing tissue, effectively replacing it both structurally and functionally, or to contribute to tissue healing[29]