Essay on Some Fact About The Prolific Theories of Bone Growth Anatomy

| - osteoblasts begin to replace the fibrocartilage splint with spongy and compact bone, forming a bulge that is initially wider than the original bony shaft

One of the key elements of regulating skeletal growth is the Osteoclasts. The Osteoclasts are responsible for initiating the bone remodeling cycle. Blood vessels and nerves are able to penetrate the bone once the chondrocytes die

In this exercise, we will examine a fresh raw chicken bone to study bone structure.

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

Materials for this laboratory included Microsoft excel to compile data, a pen and paper to record data, a 15cm ruler, string, a caliper, and a two meter ruler. Since bones often times vary in width in certain portions of the same bone due to the presence of joints and processes the bone was measured at the midpoint along its length for its true width. Measurements

Some bones were shortened, lengthened, enveloped in a thick membrane, widened, and the membrane that connects them increased, as well (Darwin 100). These changes occurred because animals were adapting to their environments. Some organisms needed to fly, to dig, grasp, or to even swim, therefore, the bones were modified

Longitudinal bone growth occurs at the epiphyseal plate, which is a thin layer of cartilage between the epiphyseal and metaphyseal bone at the distal ends of the long bones. Bone growth is the result of maturation, growth of chondrocytes, their production of bone matrix, and finally calcification (47). The growth plate is a complex structure consisting of different layers of cells, as shown in figure 3. The most immature cells, the stem cells, are found towards the epiphyseal end of the growth plate in the stem cell zone, or resting zone; the proliferating zone contains more mature chondrocytes and the hypertrophic zone contains the larger chondrocytes. The resting stem cells in the resting zone are recruited, whereupon proliferation and differentiation

Bone is a living tissue and made up of cartilage. Fibrodysplasia ossificans progressiva bone appears as normal bone tissue, but it develops in the wrong places. Osteogenesis and ossification are medical terms which refer to the formation of bone. Most bones in the human body grow and heal up after a break through endochondral bone formation, which is how FOP bones grow. Cartilage forms first and then the bone will eventually take the place of cartilage.

Generally, bone can be classified into two categories according to its structure, cortical (compact) and trabecular (cancellous or spongy) bone. Cortical bone is stiff, with 5–10% porosity, and it makes up approximately 80% of skeletal bone, including cuboidal bones, flat bones, and the ends of long bones. Cortical bone is much denser, stiffer, and stronger than trabecular bone. The average strength of a compact human bone was 105 MPa in a longitudinal compression test, and was 131 MPa in a transversal compression test. In the same experiment, the average longitudinal strength in tension was 53 MPa [39]. In contrast, the porosity of trabecular bone is approximately 50–95%, which is higher than that of cortical bones. The surface area of the

Bones contain collagen (protein), calcium salts and other minerals. Each bone is made up of a thick outer shell known as cortical bone and a strong inner mesh of trabecular bone which looks like a honeycomb. Bone is alive and constantly changing throughout life. Old, worn out bone is broken down by cells called osteoclasts and replaced by bone building cells called osteoblasts. In childhood, osteoblasts work faster, enabling the skeleton to increase in size, density and strength. During this period of rapid bone growth, it takes the skeleton just two years to completely renew itself. In adults this process takes seven to ten years.

To observe the structures of cortical and trabecular bones, the slices were observed with a Leitz Laborlux 11 with a magnification of 25X and were imaged under a magnification of 10X. Biomaterials is used alongside research of human bones. A variety of synthetic bone grafts have been utilized to fill bone defects as well as strengthen, repair and improve damaged bones. The trabecular bone structure was witnessed to that of a traditional trabecular structure with the white sections of the bones, seen in Figure 1, to be the close packed bone cells with the grey sections to be the pores, or lighter bones section, to allow less weight in the trabecular bone structure. The trabecular bone requires maximum strength with minimum mass to sustain high mineral surface area. The mineral surface area of a trabecular bone allows for cellular interaction with bone mineral material at the ends of human bones.

Ossification is the process whereby new bones are created and developed by cells named osteoblasts. An example of ossification is when cartilage is transferred to bone however, factors determine the transformation. Calcium and the consumption of vitamin D will allow the process of ossification to occur efficiently so that the bones can harden and the chances of fractures and breaks can be prevented.

The structural unit in compact bone is called the Haversian system and is organized as parallel columns, which run lengthwise down the axis of long bones. The Haversian system consists of the Haversian canal (central canal), a layer of lamellae (bone matrix), tiny spaces (lacunae) between the lamellae, osteocytes (bone cells) within the lacunae and canaliculi (small channels). Trabeculae are plates in spongy bone that branch and connect with one and another. The process of forming a new HAVERSIAN system and new Trabeculae begin with a process called remodeling, this is a process in which an existing bone is reabsorbed a new bone is laid down to replace it there several phases that occur to reach this. Phase one is Activation:

Bone at the tissue level undergoes remodeling: it is continuously being resorbed and rebuilt (or formed). A negative balance between bone resorption and formation, frequently due to excessive resorption, is the basis of many bone diseases.

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