Trabecular Bone Structure

Compact bone contains Haversian Systems, which are in concentric circles called lamellae. Haversian system contains a blood supply and the periosteum is located on the outside

Compact bone looks dense and solid, yet it is filled with passageways that serve as conduits for nerves, blood vessels, and lymphatic vessels (Marieb, 181).

The skeletal system is made up of cartilage and bone. Both bone and cartilage are connective tissues, that is, they are composed of cells in a matrix with intracellular fibers. Just imagine connective tissue as a gelatin salad with grapes and coconut. The grapes would represent cells, the gelatin the support material for matrix, and the pieces of coconut the intracellular fibers. By changing the amounts of each ingredient and adding extra substances, we can produce a material that is very hard like bone and can withstand weight or softer like cartilage which can be used as a cushioning material. In this exercise, we will examine a fresh raw chicken bone to study bone

s Flat bones Irregular bone Sesamoid bones Anatomy of a Long Bone Epiphyses Metaphyses Epiphyseal growth plate Epiphyseal growth line Diaphysis Periosteum Medullary cavity Endosteum Articular cartilage Microscopic Anatomy Compact bone Osteons Spongy bone Trabeculae Bone Formation Intramembranous ossification Endochondral ossification Cells in Bone Osteogenic cells Osteoblasts Osteocytes Osteoclasts Hormonal Control of Bone Calcitonin Parathyroid hormone Osteology of the Axial Skeleton Frontal Parietal Temporal Zygomatic arch Mastoid process Occipital Foramen magnum Occipital condyles Sphenoid Sella turcica Greater wing Lesser wing Ethmoid Cribriform plate Crista galli Nasal Maxilla Alveolar process Palatine process Zygomatic Zygomatic arch Lacrimal Palatine Inferior nasal conchae

The three long bones are Femur, Tibia, and Fibula. The long bone elongated bone consisting of a body (diaphysis) and two terminal parts (epiphyses). The diaphysis is the long central shaft, it is made up a cortical bone it is also known as compact bone and normally contains a bone marrow and fat (adipose tissue). The shaft is composed of compact bone surrounding a central medullary cavity which contains a yellow marrow. The red marrow was based on blood whereas the yellow was based store fat. A fibrous connective tissue covers and protects the diaphysis. At the end of a long bone, there is epiphysis."Metaphysis is the wide portion of a long bone between the epiphyses and the narrow diaphysis". The epiphyses have around a swollen end of the

The teeth are the hardest substances in the human body. They are built for biting, grinding and chewing, teeth are composed with most prominent inorganic minerals like calcium and phosphorus. Every tooth is embedded in a socket called gum and are made up of four different types of tissue: enamel, cementum, pulp and dentin. The enamel which is the hardest, white outer part of the tooth covers the crown which is placed above the gum. The cementum, coats the roots of the teeth firmly to the gums and jawbone. At the very centre between dentin and cementum, called pulp, where connective tissue, blood vessels and nerves are located. Dentin makes up most the tooth, guarding teeth from the wear and tear of chewing, protects against temperature changes and

The strength of the human bone depends on the microstructure contained inside. Every human bone contains osteons, these are aligned in a certain way, osteonal orientation. Usually in humans they are grouped in two antirotary system of opposite direction in the shaft of the bone (diaphysis).There is a general hypothesis that the direction of these osteons is a functional adaptation and depends on the direction of the first stress that acts on the bone. There are a few others who looked into this hypothesis but they considered a sheep tibia. Here the writer of the article is trying to determine the osteonal direction in a human femurs and evaluate the results to see if the above hypothesis was good. In this study the angle of osteonal orientation was measured and also the direction.

Directly under the enamel is the dentin, which is made up of living tissue and cellular material. Dentin is what makes up the majority of the tooth’s structure and looks a lot like bone. It contains thousands of microscopic tubules that are prone to bacterial infections that can lead to tooth sensitivity and cavities.

The bone structure of a dolphin is similar to that of a human. Starting at the base of the skull, are cervical vertebrae, the thoracic vertebrae, lumbar vertebrae, caudal vertebrae, below the caudal vertebrae are the chevron bones. The cervical vertebrae, which in dolphins is unfused and provides great neck mobility. The thoracic vertebrae support the ribs of the animal and tend to be less flexible then the other vertebrae regions. The lumbar vertebrae are more flexible dorsoventrally (up and down) than laterally (side to side). The caudal vertebrae or bones of the tail vary with species, in humans these vertebrae have fused to form the coccyx. The chevron bones function to protect elements in the tail like nerves and blood vessels from being damaged during movement of the tail. Below the thoracic vertebrae are the ribs. The ribs protect the chest cavity, like the lungs and heart.

Your body cannot make more enamel to restore damaged teeth unlike the bones in your body. Light can be seen through enamel, as it is transparent, although the part of the tooth that is either with, off-white, grey or yellow is called the dentin.

A tooth is composed of the crown and root as shown in the diagram (Fig 2.1). The crown is the visible part of the teeth [1]. Enamel is the protective covering over the surface of the crown with an approximate density of 2.9 g/cm^3. Cementum is the covering of the root that attaches the tooth to the connective tissue fibers of the membrane located between the tooth and the tooth socket to hold the tooth in place. A tooth is mainly composed of dentine. Dentine is a highly elastic internal structure within the enamel and cementum with an approximate density of 2.5 g/cm^3. Pulp is the soft tissue in the central area of the dentine that hosts blood vessels and nerves. It is important to note that enamel, dentine, and cementum are calcified. This means these three components can be used for the EPR dosimetry.

At the macrostructural level, bone is divided into the cortical (or compact) and cancellous (or trabecular) types based upon their degree of porosity or density. Histologically, it is composed of a cortical bone wrapped around older cancellous bone having irregular, sinuous convolutions of lamellae. It is still not clear whether cortical and cancellous bone matrices consist of the same material or have intrinsically different mechanical properties. Based upon the nanoindentation studies, on an

Hyaline cartilage: covers the end of the bone, smooth surface stops the bones and absorbs shock.

The skeletal system is made up of bones and joints. Bones are a dry dense tissue that is composed of calcium phosphorous and organic matter. The bones are protected and covered by a layer of fibrous connective tissue membrane called the periosteum (Brown, et al., 2015, p. 1547). There are two basic types of bone tissue: Compact Bone and Spongy Bone. Compact bones are dense smooth bones, while Spongy bones are composed of small needle-like pieces of bones and open space. Bones are then categorised according to the shape of the bone into four groups: long, short, flat and irregular. Long bones characteristically are typically longer then they are wide and generally have a shaft with heads at either ends e.g. the humerus. They are mainly compact bones. Short bones

After deriving growth factors and bone morphogenic protein from mammalian teeth successfully many researchers have supported development of bone substitute using tooth derived substance as graft material. Some studies have shown a great potential use of teeth as carrier of growth factors and stem cell. It has been reported that autogenous bone is regarded as the “gold standard” of bone graft due to its biocompatibility. However, the shortcomings of autogenous bone, such as limited amount, additional surgery, post-operative morbidities and the like are the main reasons for developing various bone graft substitutes.[1, 26]. In 2009, Korea Tooth Bank was established in Seoul for the processing of the tooth-derived materials in Seoul, and an innovative medical service has begun for bone regeneration. Today,