Bone Growth And Remodeling

Bone Growth And Remodeling Ossification and osteogenesis are two processes deemed necessary in bone. Bone growth, maintenance, repair and remodelling are a continuous process, even throughout early adulthood. Compact bone tissue provides support and protection in attempt to resists the stressors we place upon them. As we grow or encounter a traumatic experience our bones deteriorate allowing new bone tissue to be replaced (McGee-Lawrence, Westendorf, 2010). The metaphysis (mature bone region) is where the bone shaft and the distal or proximal ends of the bone join. A layer of hyaline cartilage is within each growing bone to allow the diaphysis (long bone) to grow in length (Walker, Lovejoy, Bedfford Yee, 2006). When the length of the bone has fulfilled its length, the cartilage is replaced by a bony epiphyseal (bony structure). With its thin layer the articular cartilage reducing resistance to absorb joints that have free movement. The repair of articular cartilage is minimal because it lacks irregular tissue, perichondrium (McGee-Lawrence, Westendorf, 2010). If the articular cartilage is not covering bone surface, the periosteum is put in replacement. The periosteum, acting as a tough sheath of dense irregular tissue is able to serve as an attachment point for ligaments and tendons. This gives them the ability to also assist in bone tissue nourishment and assist in fracture repair (Tortora, 2005). Bone Growth The extracellular matrix is where cells, collagen fibre and crystallised mineral salts are held. Crystallisation is where minerals combine to create the tissue hardness, the beginning of bone formation (McGee-Lawrence, Westendorf, 2010). Within the microscopic spaces of collagen fibres, an abundant amount of inorganic mineral salts such as calcium phosphate, magnesium hydroxide, fluoride and sulphate are deposited. An amalgamation of minerals allows crystallisation to occur within the framework formed by collagen fibres, initiated by osteoblasts. This is the process of calcification. A profuse amount of mineral crystals surround the collagen fibre creating the hardness and characteristics of bone. The hardness of a bone is dependent on the crystallisation formation whereas collagen fibres are responsible for the flexibility (Walker et al., 2006). Mesenchyme stem cells are the foundation of bone formation during embryonic development and have the capability of transformation into a range of cells: osteogenic, osteoblasts, osteocytes and osteoclasts cells. Osteogenic cells are located within the periosteum and within bone containing blood vessels. Their only role is to undergo cell division resulting in osteoblasts (McGee-Lawrence, Westendorf, 2010). Osteoblasts synthesize and secrete collagen fibres in combination with organic components to build extracellular matrix of bone tissue, also responsible for calcification (Tortora, 2005). Plasma proteins bring new bone formation via the synthesis of osteoid, a non-mineralised bone matrix. When osteoblasts trap themselves with an excess amount of extracellular matrix, they are then called osteocytes. Within the Osteoblasts, many receptors are found in bone marrow assisting in regulating osteoclastic bone remodelling. The amount of osteoclast formation is determined by the level of receptor activator of nuclear factor KB-ligand (RANKL). If there is a defect of RANKL, a patient may suffer Paget Disease. This is when bone abnormality can occur; both resorption and formation (Walker et al., 2006). Osteocytes, also known as mature bone because of their function are located in a hardened bone matrix (lacuna). They are the key cell in bone tissue, maintaining daily metabolism (exchange nutrients and waste in blood) and secrete protein such as sclerostin to reduce bone formation (McGee-Lawrence, Westendorf, 2010). They have the capability to communicate with each other to exchange nutrients from capillaries containing nutrient-rich fluids. Osteocytes also communicate with osteoblasts and osteoclasts, signalling both when and where to resorb and form new bone (McGee-Lawrence, Westendorf, 2010). Osteoclasts are the major resorptive white blood cells containing lysosomes or digestive vacuoles filled with hydrolytic enzymes. The release of enzymes digests protein and mineral components in the extracellular matrix of bone, as part of the maintenance, repair and growth of bone. This process is called resorption. Once completed, they revert to their parent cell or become inactive (Walker et al., 2006). Bone remodelling Bone remodelling is an ongoing procedure from new bones at with to healing period of fractures. The strength of a bone is determined by the stressors placed upon it whilst in the remodelling phase. The most common fractures paramedics face on road is:  · Compressed most common in old age, osteoporosis  · Spiral ragged break, mostly seen in sports injuries  · Depressed pressed inwards, skull fracture  · Greenstick Incomplete break, most common in children First action to take place in a fracture is formation of hematoma. Blood vessels are broken, resulting in a leakage from the torn ends (Walker et al., 2006). A blood clot around the site of the fracture usually within 6 to 8 hours following the injury is called hematoma. As clotting continues and fracture hematoma forms, blood flow to the site of injury becomes minimal, causing bone cells to die. Swelling and inflammation is the result of dead bone cells, producing additional cellular debris. This allows phagocytes and osteoclasts to eliminate damaged tissue. This process should take 2 to 3 weeks to conclude (Tortora, 2005). The help of new blood capillaries in the fracture helps growing connective tissue called procallus. Fibroblasts (producing collagen fibres) and osteogenic cells attack the procallus to assist in connecting ends of the broken bones. Osteogenic cells transform into chondroblasts where healthy bone cartilage are developing and become fibrocartilage. Within 3 weeks, signs of bone tissue repair begin to show. This action is successful when the procallus is transformed into a fibrocartilaginous. Whiles this is occurring, phagocytes continue to remove any debris surrounding the fracture (McCance, Heuther, Brashers Rote, 2010). Osteogenic cells are later converted into osteoblasts to produce spongy bone trabeculae, a microscopic tissue. Trabeculae join the living and dead portions of the bone. After 3-4 months, Fibrocartilage changes into bony callus, a spongy bone (McCance et al, 2010). The final phase of bone repair is remodelling. Osteoclasts gradually resorb original fragments of broken bones as compact bone replaces spongy bone. If all cells are working in a healthy patient, detection of fracture line under radiograph is unseen. As the stressor on the bone increases, signs of thickness may later show (McCance et al, 2010). Bone remodelling is a slow process of removing old tissue and producing new bone tissue. As we grow, bone tissue goes through maintenance, repair and development in order to cope with the stressors. The remodelling of bone tissue only occurs when a patient has gone through a traumatic injury; this is where the housekeeping phagocytes are active and inflammation to ensure bacteria do not enter blood vessels, causing further damage.

Efficient Financial System: Fuel for Economic Growth Essay

The financial intermediaries and financial markets which form a part of the financial systems are the pillars for economic growth leading to a more practical resource allocation as they decrease the costs of moving funds among lenders and borrowers, thus helping to provide information symmetry between both the parties. However, the inability of these pillars to function together may result in operational inefficiencies of the economy, negatively affecting the economic growth. The reduction in poverty through greater access to finance and efficient allocation of societal savings promotes financial sector development leading to economic growth. To understand how an efficient financial system fosters economic growth, we need to understand the ways in which such a system eases goods and service exchanges through provision of payment services, help to collect and mobilize a large number of investor savings, gather and develop enterprise information and potential investment projects, thus ensuring allocation of societal savings to their most fruitful use, scrutinize investments and wield corporate governance there by reducing the inter-temporal risk and liquidity. However, the disparity across countries with respect to the efficiency with which financial markets and institutions lower the operation costs and information asymmetries, with significant ramifications for economic expansion and development is noteworthy. (http://www. treasury. govt. nz/workingpapers/2004/twp04-17. pdf) To have a better understanding of how an efficient financial system may lead to economic growth, let us consider the following example. With a stable financial institution in place, there have been recent introduction of a 40 year term mortgage loans in the U. S, however in comparison, in many developing countries lending for housing is limited to five year term loans if at all available. The lending ratios i. e. , the available loan per 1000 people vary from four loans per 1,000 people in Albania to almost 800 loans per 1,000 people in Poland. The interest rate spreads i. e. , the disparity between deposit and lending rates – vary classically between 2% and 4% in developed financial systems such as USA and Europe as compared to being over 30% in Brazil. Development of the financial sector promotes economic growth through more well-organized allocation of resources and growth due to productivity instead of providing it through the scale of savings mobilization or investment. This promotes economic development by extending entree to external finance thus improving resource allocation and increase in efficiency of reallocation of investment funds across industries. Financial development also helps to diminish the force of external shocks on the domestic economy, it being a vital determinant of the balance of trade structure, thus, providing countries with a relative advantage, in those industries which are mostly dependent on external finance. Thus, given the significance of an efficient financial system development for economic growth leading to poverty reduction, academicians and policy makers would be similarly interested in and concerned about the building blocks for a strong and efficient financial system. Carlton- Home Loan For the purpose of investment, a loan for $300,000 in Carlton for ten years has several sources and costs involved. It is best to choose a mortgage loan with fixed rate interest and avail the same from the bank. The rationale for the choice is explained below, considering the factors that are involved in the choice, the advantages and its cost. Choice of the Source The home loan market is dynamic and offering various kinds of loans ranging from mortgage loan, home equity loan, reverse mortgage etc. These are further replete with choices like interest only loans. Consideration the loan for buying an apartment for investment purpose, there are sources available like broking houses, mortgage loan companies and banks. All these sources have a different way of operation, and offer various loan products. The choice of the type of loan depends on certain questions like purpose of the loan, the period for which one plans to stay in the home, the tenor of the loan preferred, preferred amount of down payment, frequency and structure of payment. Each different loan source has its pros and cons. One can select loan types from a choice of Fixed Rate Mortgages (FRM), Adjustable Rate Mortgages (ARM), Balloon Mortgages, no fee and no point programs etc. (Source: â€Å"Factors affecting mortgage rates†) For the home loan into consideration, looking at the investment purpose and a horizon of 10 years, the fixed rate mortgage loan happens to be the right choice. Moreover, it is best to avail the loan directly from the bank, rather than a broking house.

Life Has a Hopeful Undertone

McCarthy follows a father and son who are struggling to survive after some global apocalypse. The father struggles to keep his faith and â€Å"carry the fire,† he starts to question his faith in humanity him believe to have hope in the most difficult of times. Despite civilization falling apart, in the novel The Road by Coral McCarthy hope is revealed to be a major theme by symbolism in the fire and the boy. The man and boy often find themselves in difficult situations.The boy considers that e would be better off dead because his loss of hope. He says he would be better off with his â€Å"mom† (55), who is dead. The man tells him that he has to â€Å"carry the Although it is not directly said in the novel, the fire is implied to be related to hope and goodness. The father and son are some of the few survivors who refused to exploit human beings, because they have not given up and lost faith in their morals. Hope helps them find alternatives from cannibalism. Even when they were â€Å"starving†(129). They still refuse to eat any human flesh.In the novel, the cannibals represent a fallen society that a man and boy have to live through. The boy is a symbol hope and is one of the â€Å"good guys†(77). Those who carry the fire have not given up hope and need to preserve the faith and sake of humanity, because If the two characters decide to eat a charred human Infant (198), everyone on Earth would be killing each other and ending humanity; there would be no hope or love left, there would be nothing or no one left to live for. The man and boy both believe â€Å"nothing ad is going to happen† (83), to them because they are carrying the fire.Ultimately at the end of the novel the man ends up dying, but hope continues to live on In the boy, who meets a new family that Is â€Å"carrying the fire† as well (284). This shows that even In hard times you can still have hope that things will get better. When his son was born the man s ays that the boy was â€Å"beyond the window Just gathering cold, the fires on the horizon† (59). The man found hope when his son was born, and found another reason to live. The mother states â€Å"the boy was all that stood between him and death†(29).The child was an embodiment of hope and salvation; he was a light In the darkness. The man thought of his son as God; he asked Ely noon thought he was an angel? What If I said he was God? â€Å"(172). The man saw his son as a symbol of hope Is a place where hope was no longer relevant. Overall, hope In a ruined society can begin the dullness, but The Road by Coral McCarthy shows that hope can still remain. Hope when a salvation Lies In ruins can easily be forgotten between the fight with death and the desperation to live, but It remains as the only thing that can begin to rebuild humanity again.Life Has a Hopeful Undertone By liable given up hope and need to preserve the faith and sake of humanity, because if the two cha racters decide to eat a charred human infant (198), everyone on Earth would the end of the novel the man ends up dying, but hope continues to live on in the boy, who meets a new family that is â€Å"carrying the fire† as well (284). This shows that even in hard times you can still have hope that things will get better. When his son was death†(29). The child was an embodiment of hope and salvation; he was a light in the darkness.The man thought of his son as God; he asked Ely muff thought he was an angel? What if I said he was The man saw his son as a symbol of hope is a place where hope was no longer relevant. Overall, hope in a ruined society can begin the diminish, but The Road by Coral McCarthy shows that hope can still remain. Hope when a civilization lies in ruins can easily be forgotten between the fight with death and the desperation to live, but it remains as the only thing that can begin to

King Arthur, Sir Gawain and Superman Essay - 1160 Words

Rick Riordan said â€Å"A hero can go anywhere, challenge anyone, as long as he has the nerve.† and he is correct because that is exactly what King Arthur, Sir Gawain and Superman do. They risk their very own lives and put themselves in front of others with their courageous acts from fighting great green knights to fighting the towns super villain. They do it all just to protect their city. The culture of the Medieval Ages valued with bravery and courtly love which was reflected in the exploits and adventures of King Arthur and Sir Gawain; the modern culture trait of compassion is embodied in the modern hero Superman. â€Å"Chivalry based its rules first on the knights duty to defend the people he had promised to defend. To run away or give up was†¦show more content†¦Comparing it to Superman it shows his love life does not compare to this at all. Chretiens Lancelot is a classic courtly lover. His total devotion to Arthurs queen gives expression to the twelfth centurys exploration of a new code of elegant courtship. (Medieval Arthurian Romances) Launcelot, falling in love with King Arthur’s queen, wife, Gwynevere is known as a courtly lover because he risks his life just to save her even though they are not married showing his true devotion to the King and Queen. According to Allen â€Å"King Arthurs favorite knight, Sir Launcelot, has fallen in love with the kings wife, Gwynevere. The secret love affair is exposed by Sir Modred, Arthurs son by another woman, and Gwynevere is sentenced to burn at the stake. While rescuing the imprisoned Gwynevere, Launcelot slays two knights who, unknown to him at the time, are the brother of Sir Gawain, a favorite nephew of Arthurs. After a reconciliation, Launcelot returns Gwynevere to Arthur to be reinstated as queen.† (Allen 248) By this statement the reader can conclude they are resembling bravery in Sir Launcelot to risk his life to save a woman that is not his, although Gwynevere is not his wife, but lover, he risked everything to save her life. Also act resembles courtly love. This idea is alsoShow MoreRelatedInfluence Of Medieval Literature On Modern Films1169 Words   |  5 Pagesmedieval romantic literature influence how modern films are made? Romantic literature started during the mid-12th Century (â€Å"Romance,† par.1). Medieval romances are stories and plays in which kings, knights, and damsels in distress go on some sort of adventure (from Sir Gawain and the Green Knight from Morte d’ Arthur). In addition, medieval romances consist of heroic figures showing acts of chivalry. As the years have passed, medieval romance has been portrayed in numerous screenings and productions.