Haematopoiesis Located In Bone Marrow Section Biology Essay

Haematopoiesis Located In Bone Marrow Section Biology Essay Haemopoiesis also known as haematopoiesis located in bone marrow section of an adults and lymphatic tissue is the process of production of blood cells and platelets which continues throughout life, replacing aged cells which are removed from the circulation by which immature precursor cells expand to mature blood cells. This process thesis and how it works is known as monophyletic theory. The cellular blood components are precursor to haematopoietic stem cells (HSC) that forms blood cells and immune cells. Blood cells (BC) are significant in maintenance of immune system in all types of cells in the body which prompt the BC to constantly maintain self renewal. Haemapoiesis stem cells therefore can proliferate, differentiate and even undergo cell death called apoptosis in various types of specialized cells in the body. The morphology and growth of BC sometimes occurs outside the bone marrow cells called extramedullary haemopoiesis. This is abnormal condition associated with Myelofibrosis caused by disorder in the bone marrow due to abnormal stem cell results or replacement by collagenous connective tissues. The sources of HSC are bone marrow, peripheral blood, umbilical cord blood, Foetal Hematopoietic, Embryonic Stem Cells and Embryonic Germ Cells. The vascular compartment of bone marrow is used to supplied nutrient artery and open into sinuses. The sinus carries the blood from the bone marrow to the body. HSCs have two kinds and include long term stem cells which incorporate transplantation of a new marrow cells to lethally cancerous patients and restore its haemopoietic system for longer periods and short term progenitor which are unable to renew themselves for longer period but immediately regenerate all types of blood cells. The success of been able to inject healthy cells from compatible donor to patients receiving chemotherapy successfully and recipient recover by regaining full functioning healthy blood cells is deemed to have completed stem cells. Large amount of new blood cells are constantly been produced in the blood circulation ensuring steady flow in the peripheral circulation. This type of stem cells is known as pluripotential stem cell (PSC). Pluripotent stem cell however differentiates into other stem cells known as unipotential stem cells: erythropoiesis, monocytes, granulopoiesis, thrombopoiesis and lymphopoiesis are specially multiplied into precursor specifically to individual mature blood cells. Erythropoiesis is the process used to describe red blood cells (erythrocytes) formation exclusively in the red bone marrow involving matured nucleated precursor into erythrocytes. The yellow bone marrow initially composed of fats and subsequently changed to red bone marrow from greater affinity of red blood cells needs. Haemocytoblasts is the precursor of erythrocytes lasting for few days and involved around four mitotic divisions of cells given rise to 8 to 16 more cells. The kidney initiates RBC production in mature cell by responding to lack of oxygen in the blood and secret special hormone called erythropoietin. This hormone is then transferred to red bone marrow and begins production of red blood cell. The RBC fills up the blood capillaries for distribution in the body. After few days the RBC is strong enough to serve oxygen to the body and consequently subsided after few months and loses its affinity to continue oxygen distribution and rupture. The ruptured RBC is then taken up by the spleen for recycled to form new RBC. Monocytes is a type of white blood cells that mature to much larger cells called macrophages and plays major role in immune system of the body that destroy dead cells or tissues damaged and cancer cells. Produced in the bone marrow and develop from nucleated precursors, the monoblast and promonocyte and then goes through the bloodstream for circulation to the spleen, lymph nodes, liver,bone marrow and lungs. Mature cells in monocytes life span is around 3-8 hours with full antigenic stimulation of T and B lymphocytes. Thrombopoiesis is a Platelets formed in the cytoplasm cell called megakaryocyte inside bone marrow with maturity within 10 days from much larger stem cells, megakaryoblast . The platelets formation penetrates into the blood vessels to prevent bleeding, assist clots formation to prevent bleeding and repair damages to blood vessels. Macrophages eventually destroy the platelets in the spleen and liver. Granulopoiesis are formed in the red bone marrow (RBM) called granulocytes and subdivided into three types of white blood cells (WBC); eosinophils, neutrophils and basophils and are grouped in the same stem cells called myeloblast. Granulocytes are produced by the continuous lobulation and condensation of the nucleus, loss of RNA cytoplasmic granules development. A developed cell goes through sinus endothelium where half of the granulocytes circulate to the internal surface of blood vessels and the other half circulates in the blood vessels for exchange. Half of the granulocytes eventually disperse from the circulation in response to requirement in the tissues. Lymphopoieses are precursor to lymphoblasts and prolymphocytes produced in bone marrow. Immature cells are transferred to the lymphoid tissues and thymus, with further division with similar antigens to T cells, B cells and NK cells. They mediate composite and immune effectors. Blood cells (BC) are significant in maintenance of immune system in all types of cells in the body which prompt the BC to constantly maintain self renewal. Haemapoiesis stem cells therefore can proliferate, differentiate and even undergo cell death called apoptosis in various types of specialized cells in the body. The morphology and growth of BC sometimes occurs outside the bone marrow cells called extramedullary haemopoiesis. This is abnormal condition associated with Myelofibrosis caused by disorder in the bone marrow due to abnormal stem cell results or replacement by collagenous connective tissues. The sources of HSC are bone marrow, peripheral blood, umbilical cord blood, Foetal Hematopoietic, Embryonic Stem Cells and Embryonic Germ Cells. The vascular compartment of bone marrow is used to supplied nutrient artery and open into sinuses. The sinus carries the blood from the bone marrow to the body. HSCs have two kinds and include long term stem cells which incorporate transplantation of a new marrow cells to lethally cancerous patients and restore its haemopoietic system for longer periods and short term progenitor which are unable to renew themselves for longer period but immediately regenerate all types of blood cells. The success of been able to inject healthy cells from compatible donor to patients receiving chemotherapy successfully and recipient recover by regaining full functioning healthy blood cells is deemed to have completed stem cells. Leukemia and Lymphoma are some of the cancer of the blood associated with treatment by HSCs. The process relates to the patients defective white blood cells causes by cancer having been destroyed using chemotherapy and replaced with bone marrow transplant matched with donor. Donor are usually from patients family with similar leukocytes antigens. Cancer of the blood are acute or chronic myeloblastics leukemia, multiple myeloma, non-Hodgkins lymphoma and Hodgkins diseases. Name the systems used to classify acute lymphoblastic leukaemia(ALL) and acute myeloid leukaemia (AML). (word limit: 20 words) (2 MARKS) French-American-British (FAB) classification and the World Health Organization (WHO) classifications are two subtypes used in classification of AML and ALL. Define leucocytosis and thrombocytopenia. (word limit: 75 words)(5 MARKS) Leucocytes is a conditions of an abnormal increase of white cells in the blood due to infections. Total white blood cells is approximately 4400 to 11,000 cells/microL. Excess to the value of 50,000/microL, attributed to leukemia is called leukemoid reaction. Thrombocytopenia is a condition where there is abnormal decrease in platelets counts, rendering inability for clot formation resulting in excessive bleeding. Causes can be due to low platelets in bone marrow, intravascular and extravascular. Define leukaemia and state the four main divisions of the disease. (word limit: 70 words) (10 MARKS) Leukaemia is a malignant (cancer) of the bone marrow characterized by uninhibited proliferation of abnormal white blood cells. Symptoms include enlargement of liver, lymph nodes and spleen, anaemia, blood clotting retardation. Four major types of leukaemia are; Acute lymphoblastic leukaemia (ALL) and Chronic lymphocytic leukaemia (CLL) classified as Lymphocytic or lymphoblastic, Acute myeloid leukaemia (AML) and Chronic myeloid leukaemia (CML) classified as Myelogenous leukemia State the typical manifestation of someone presenting with acute leukaemia including the blood film morphology. (word limit: 200 words) (5 MARKS) Most common symptons includes abnormal bruising and bleeding (thrombocytopaenia), anemia, bleeding gums or irregularity in menstrual period and infections. Anaemia and hypermetabolic state are attributed to fatigue, malaise, weight loss, chest pain and tachycardia. Granulocytopenia can progressively lead to potential life threatening bacterial infections. Developing infection frequently in eyes, nose and mouth known as neutropaenia, trace of blood in urine, fine rash dark red spots called purpura. Sign of fever, abnormal heamostasis are mostly common. Patients may sometimes shows lesion in soft tissues, spina dura and cranial representing tumour of leukaemia cells called granulocytic sarcoma or chroma. Periosteal infiltration and bone marrow may initiate joint pain (Arthralgia) in children with ALL. Meningitis causing vomiting, seizure, papilledema and headache is rare. Blood film morphology diagnosis of AML shows presence of more than 20% myeloblasts in blood cell. Cells appear to be smudge with decrease in thrombocytes. Elevated count of leucocytes 135.3 x 109 /L and thrombocytopenia of 26 x 109 /L indicates signs of acute leukaemia. In AML, Auer rods appear smaller in size, absent of granules, lower RBC counts and appear smaller in morphology. Also ALL contains no granules State the typical manifestation of someone with chronic leukaemia including the blood film morphology. (word limit: 200 words) (5 MARKS) (word limit: 230 words) (15 MARKS) Chronic leukaemia from mature cells is a slow progressive symptom that goes unnoticed for months. Disease is normally notice during normal routine blood test. Immediate treatment is not imminent and may involve chemotherapy treatment in tablet from. Two types of chronic leukaemia: Chronic myeloid leukaemia (CML), cancer of the myeloid cells, and chronic lymphocytic leukaemia (CLL), cancer of the lymphocytes. Chronic lymphocytic leukaemia (CLL) is the most common type characterised by an increased number of lymphocytes (WBC). The lymphocytes are unable to perform normal process of responding to infections by producing antibodies needed to destroy bacteria. Symptoms may be tiredness (anaemia) due to lack of RBC, continuous infections due to WBCs healthy shortages in fighting infections, abnormal lymphocytes in lymph glands causing swelling in neck and arm pits or groin, also swelling in spleen, Low platelets in blood leading to bruising or bleeding without injury, weight loss, fevers and night sweat. Test in blood film morphology indicates nuclei appearance is rounded and condensed chromatin. High level of beta-2-macroglobulin protein in the blood indicates advance CLL. Appearance and large amount of lymphocytosis in the blood more than 10,000 lymphocytes/mm ³ of blood shows presence of the disease. Patient with CLL often have low red blood cells and blood platelets in the body. Explain the following techniques and give one example for each, of application in the diagnosis or monitoring of leukaemia: (word limit: 230) (15 marks). Cytochemistry Is the staining methods use to study, identify and localization of various chemical compounds within living cells and activities of acute leukaemia. The most simplify cytochemistry method of diagnosing leukaemia is Myeloperoxidase (MPO) staining which can be completed within minutes. Its main function is to differentiate AML and ALL. Lysosomal enzyme stored azurophilic granules of neutrophils and monocytes. Used in basophils and eosinophils demonstration. A heme pigmentation react to its green colour secretion found in neutrophils. Immunophenotyping Immunophenotyping is use to analyze heterogeneous populations of cells based on the antigens phenotype according to their resemblance of interest. Example is leukocytes from peripheral blood extract from lymph nodes, leukaemia and lymphoma specific to differentiate cancer cells to normal of immune system. Immunophenotyping is used on a daily basis by pathologist from normal biopsies to bone marrow biopsies from various patients. Method mostly used to analyze and sort T-lymphocytes into subsets based on CD antigens is flow cytometry techniques. Samples of cells are analyzed in a multi-well plate with aid of fluorescence or scatter laser light to sort out population by immunophenotypic markers type. Cytogenetics The branch of genetics specialized in the studies of relationships between the structure of cell division and chromosomes relating to variation in phenotype and genotype. Test are carried out in blood samples and bone marrow from leukaemia patients to analyse abnormalities in chromosomal link with certain disease. Fluorescent in situ hybridization (FISH) is one of the methods use in routine analysis of cytogenetic band, molecular cytogenetic and G-Banded chromosomes in leukemia against normal chromosome. What is the Philadelphia chromosome? Give an example of where this is commonly found. (word limit: 120 words) (5 MARKS) Philadelphia chromosome (PH) or Philadelphia translocation is a specific chromosomal abnormality that causes chronic myelogenous leukemia (CML). It is an abnormally chromosome 22 involved in an exchange with chromosome 9 which occur at the site of single bone marrow cell and can also be located in form of acute lymphoblastic leukemia (ALL). The clonal process expands to the leukaemia and was the first major mutant cell found in malignancy which led to the CML cells combination of BCR-ABL gene protein. These genes belong to chromosome 22 and 9 respectively. The activities of both PH chromosome fused together causing uncontrolled malignant in the cell is a strong indication of pathogenic disease. The drug mesylate (Gleevec) was introduced through understanding of this mechanism to aid in cancer treatment. State the difference between stem cell and bone marrow transplants. (word limit: 100 words) (4 MARKS) Stem cell transplantation is a method where the stem cells are obtained from the peripheral blood using aphaeresis method. Aphaeresis assists in stem cells filtrations and avoids unwanted blood. When stem cells are obtained from the outpatient donor from the blood stream, they are less invasive and patient can recover very quickly at home. Stem cell harvested from the bone marrow using fine needle inseted into the hip joint however required critical method from in patient to be hospitalized and put under general aneshesia for continue monitoring. Stem cells collected from the bone marrow are much richer in stems compare with stem collected from the peripheral blood. State the difference between autologous and allogenic transplants. (word limit: 50 words) (4 MARKS) Difference between an autologous transplant is when patients own blood forming cell are collected for use in transplataion later, while an allogenic transplant relies on cells collected from volunteers bone marrow. The donors tissue type must be compatible to the recipient to avoid miss match.

Economics Commentary Essay

The article I have chosen to base my commentary on is â€Å"SpiceJet buys 30 Q400† aircraft from the times of India (website) and the article was published on 30th of august, 2011. As the title suggests the article discusses about the recent acquisition made by SpiceJet of 30 Q400 aircrafts from Bombardier in order to reach out to more of the tier 2 and tier 3 cities in India, where there is a potential demand which has not been yet met entirely. These cities include Aurangabad, Bhopal, Indore, Mangalore, Rajahmundry, Tirupati and Vijayawada also SpiceJet will start operating direct flights to cities that is not easily available such as; from Hyderabad to Goa and Madurai, Nagpur to Pune and Bangalore to Vizag. This plan to improve air connectivity by SpiceJet has given a lot of satisfaction to many people as their travel has been made much more easier for many citizens of India. Also this the first time that any airline in India has bought these new changes and it allows the company to have monopoly, when concerning these particular routes. Through these changes SpiceJet will be able to increase their customer base and reach out to a more niche market that had been previously neglected by them. This improvement in their route and by providing more aircrafts SpiceJet will enable them to increase their supply thus resulting in their prices to decrease (as can be seen on diagram 1). Moreover the Q400 aircrafts are comparatively much more fuel efficient which not only decreases their cost and hence allows them to offer â€Å"affordable journey to the common people† but also improves their public image because it promotes them as being environmental friendly and hence increase their demand thus bringing about an increase in the equilibrium quantity and price as well (as can be seen on diagram 2). Additionally it makes sure that SpiceJet would be less prone to criticism from NGOs or other pressure groups. Q400 is considered to be the â€Å"best short-haul plane† and comparatively is more comfortable than other planes like it. This will increase the demand of this series of aircraft and most probably more of airlines companies would like to buy flights from bombardier these and hence the price would be increased (as can be seen by figure 3). In addition to this The Q400 aircraft due to its comfort would also benefit SpiceJet as more passengers would like to travel through it compared to other airlines thus causing the demand curve to shift upwards and thus allowing the prices to increase even further (as can be seen by figure 4). The Q400 aircraft are not only going to benefit SpiceJet but also millions of people and India as a whole since this would cause a drastic improvement in communications. Also it will set a trend for other airlines to also offer more routes and hence force the prices to go even lower as the competition will increase and the demand would become comparatively elastic (as can be seen by diagram 5).

Human life-span Essay

The answer in my own broad based opinion based on what I have read, is that the term, â€Å"Learning† is a cognitive process of acquiring new concepts and skills, in order to complete a task which in-turn increase’s knowledge and understanding of the subject area to be learnt. In addition, individuals will be able to build on past experiences to identify how a situation could be improved, and then with this knowledge make actual improvements. Furthermore, learning is influenced from the environment in which we find ourselves, which reflects greatly in our behaviour. Moreover, it is continuum throughout the human life-span. In comparison the term, â€Å"Development† refers to the biological process by which a human organism grows and functions through its life-span. Development can be monitored by physical growth, and a marked change in performance which is usually associated with progression of increasing knowledge and skills. Development happens gradually over a period of time, allowing achievements to be built upon and improved, which is similar to the learning process. Development seems to be sequential with age, and I believe what happens in the early stages of development can have a significant affect in the later stages of development. Furthermore, development can be influenced by our own personal experiences within the environment. It is important to understand that there is a clear difference between learning and development. Learning occurs within specific situations and development is linked to functionality and physical growth, however, they are closely related, but have separate meanings. Educational pioneer, Friedrich Froebel (1782-1852) urged early year’s educators to respect the sanctity of children learning and developing new skills through this statement: â€Å"We grant space and time to young plants and animals because we know that, in accordance with the laws that live in them, they will develop properly and grow well. Young animals and plants are given rest and arbitrary interference with their growth is avoided, because it is known that the opposite practice would disturb their pure unfolding and sound development; but the young human being is looked upon as a piece of wax or a lump of clay which man can mould into what he pleases,† (www. Geocities. com). The origins of learning theory are in an area of philosophy called â€Å"Epistemology,† a field concerned with how we acquire knowledge. Two philosophical traditions emerged from the writings of the ancient Greek philosophers, Plato and Aristotle. These traditions are nativism, (Plato) and empiricism, (Aristotle). In the early seventeenth century before the beginnings of modern Psychology, there was a philosophical debate between the empiricists and the nativists, known more commonly today as the nature-nurture debate. The nature-nurture debate is another example of determinism. The debate is concerned with what causes something to develop. On one side, nativists see development as arising from innate factors – from inherited characteristics. On the other side, empiricists see development occurring because of experience and learning. British philosopher John Locke, (1632-1704) the founder of empiricism, advanced the hypothesis that children learn primarily from external forces, he implied: â€Å"Without nurture, we are nothing† (Haralambos & Rice 2002, p. 761). Empiricists believed that the human infant is born with no skills or knowledge; they refer to the infant as a, â€Å"Tabula rasa,† or â€Å"Blank slate. † The rationale behind this idea is that the knowledge and skills will be, â€Å"Written on† the child by the knowledgeable hand of experience, and influenced by environmental factors. Furthermore, the infant will learn through instruction from others, in addition too their own direct experiences, which in-turn will determine their achievements. Nativists (such as Jean- Jacques Rousseau 1712- 1778) in contrast, argue that we are born with innate intelligence, in addition to genetic inheritance which determines intellectual achievement and, to some extent, personality. William Mcdougal, (Nativist- 1908) states: â€Å"The human mind has certain innate or inherited tendencies which are the essential springs or motive powers of all thought and action, whether individual or collective, and are the bases from which the character and will of individuals and of nations are gradually developed,† (Haralambos & Rice 2002, p.761). A modern form of the, (Nurture debate) relating to learning theory was proposed by B. F Skinner (1904-1990) in the form of behaviourism. The Behaviourists believed that human behaviour is learned. Behaviourism is primarily concerned with observable and measurable aspects of human behaviour, in relation to what we can see, how people react, in addition to how people behave. Behaviour theorists define learning as nothing more than an acquisition of new behaviour. Skinner’s theory is based on the idea that learning occurs through a process of reinforcement. He believes changes in behaviour are the result of an individual’s response to events, (stimuli) that occur in the environment. A response produces a consequence, for e. g. when children utter sounds and words which are to become their native language, and are greeted with a positive response. This positive response is the reinforcement which encourages the child to repeat the sound of the word, which in turn reinforces learning. Furthermore, behaviourists support the, Transmission Model of learning (Nurture) as the model uses the hand of experience, the knowledgeable adult to nurture the child through the learning process, enabling them to control what learning takes place. The Social Learning theory developed from behaviorism. Albert Bandura emphasizes the importance of observing and modeling the behaviors, attitudes, and emotional reactions of others. Bandura, (1977) states: â€Å"Learning would be exceedingly laborious, not to mention hazardous, if people had to rely solely on the effects of their own actions to inform them what to do. â€Å"

Argumentation and Fallacies Reductio Ad Absurdum