Hematology Coursework Example | Topics and Well Written Essays - 1750 words

Hematology - Coursework Example Neutrophils contain primary (azurophilic) and secondary granules. Primary granules contain a enzymes and molecules that play a role in killing microbes, including hydrolases, elastase, myeloperoxidase, cationic proteins, defensins, and bactericidal/permeability-increasing protein. Secondary granules contain unique molecules such as lactoferrin, vitamin B12–binding protein, NADPH oxidase (which produces hydrogen peroxide), and chemoattractants receptors. The nucleus of neutrophils normally contains up to four segments, which is why they are also known as polymorphonuclear (PMN) cells. Neutrophils are phagocytes that perform the functions of immune surveillance and in situ elimination of microorganisms and cell debris. They circulate in the blood and also line vascular endothelium. They are the first immune cells to arrive at the site of inflammation through chemotaxis, and rapidly extravasate into the surrounding tissues. In the tissues, they release the degradative enzymes in their secondary granules that kills bacteria but also causes tissue destruction. They carry out phagocytosis to engulf opsonized cell debris and microorganisms that they come in contact with. The vacuole with the phagocytosed organism is fused with the primary granules, causing the oxidative and antimicrobial enzymes to access and kill the ingested microorganism. Neutrophils self-destruct after a life of 1-4 days in tissues. - Lymphocyte There are two main types of lymphocytes: B cells and T cells. They are round cells with a large, round nucleus and scant cytoplasm. Lymphocytes govern the acquired arm of immunity, they are responsible for mounting a specific host immune response targeted against a particular invading organism. B cell precursors are produced in the bone marrow, but they migrate to the peripheral lymphoid organs, where they undergo maturation with antigen exposure to plasma cells. An important function of plasma cells is to produce immunoglobulins (Igs). A major func tion of immunoglobulins is to act as antibodies. Antibodies help degrade and clear foreign substances by binding to specific microorganisms’ molecules called antigens, a process termed opsonization, and produce specific results including antibody-mediated cellular toxicity and activation of the complement system that destroys foreign cells. There are hundreds of thousands of different B cells in the body at a time, each is capable of producing an immunoglobin specific to a microbe, this arsenal of B cells makes the body capable of mounting an antibody response against nearly every possible virus, bacteria, fungus and protozoa that can be encountered. T cells similarly undergo maturation in peripheral lymphoid organs and the thymus, they produce ‘T cell receptors’ specific to foreign microbes. Activation of T cells requires interaction of the T cell receptor with an antigen-presenting cell; activated T cells are responsible for delayed-type immunity. There are 2 m ain types of T cells: CD4 cells, called T helper cells, which produce cytokines that activate B cells (by IL-4 and IL-5), macrophages (by IFN-gamma) and other immune cells. CD8 cells, also called T cytotoxic cells, destroy cells with intracellular microorganisms such as M. tuberculosis, virus-infected cells, tumor cells and allografts. - Monocyte Monocytes are circulating agranulocytes with a kidney-shaped nucleus. They have two main functions: phagocytosis of microorganisms, and presentation of antigens to T cells to activate the acquired arm of immunity. They are released from the bone marrow and circulate in blood for about 72 hours before migrating into tissues to transform into macrophages to carry out their functions. They have surface receptors that can recognize bacteria, such as Toll-like

First American Physicist Benjamin Franklin Research Paper

First American Physicist Benjamin Franklin - Research Paper Example Ben Franklin’s life shows that only those people who dare to risk securities of home, have a strong desire to learn continuously and have a great sense of humor, can lead a happy, content and meaningful life. Hence, for anyone who desires to lead a meaningful and joyful life, and desires to live every moment of life to the fullest, the characters and life of Ben Franklin can be great inspiration, as he is an epitome of qualities that lead to success and happiness in both, the personal and the professional life. Early Years Ben Franklin was born in Boston, Massachusetts, on January 17, 1706 (Glass, 2004, p. 4). Franklin had sixteen siblings and he was the fifteenth child of his parents (Glass, 2004, p. 4). He went to school at the age of eight but left the school at the age of 10 to become an apprentice to his father (Glass, 2004, p. 4). He was exposed to work life very early. However, he was very fond of reading books and never stopped learning new things (Glass, 2004, p. 5). His mind was active, sharp and curious. Ben learned how to make soaps and candles in his father’s shop (Nettleton, 2004, p. 5). However, he never liked making it and enjoyed reading better (Glass, 2004, p. 6). Even though he was able to attend the school only for two years, his interest in reading books remained intact (Nettleton, 2004, p. 6). ... 6). The interest in reading and gaining knowledge from books developed his skills and business acumen. Moreover, he learnt how to be â€Å"good, just and prudent in the conduct of life† from his father (Russell, 1926, p.5). While working under his father, Ben developed interest in different tools of making artifacts by watching â€Å"joiners, bricklayers, turners, braziers and other artificers at work† (Russell, 1926, p.5). This helped him later in life in making his own tools to conduct different experiments in his laboratory (Russell, 1926, p.5). However, Ben never liked his father’s business and also did not intend to become a clergy, as his father wanted him to be (Russell, 1926, p.7). After some time, he joined his brother in printing shop (Glass, 2004, p. 6). However, Ben soon realized that he will have to make a separate way for himself, as his relationship with his brother was not going smooth. Independent Path Benjamin Franklin’s brother James was a printer (Glass, 2004, p. 6). Ben joined his brother as an apprentice and started learning how to make new papers at his printing shop (Nettleton, 2004, p. 11). At the time he joined his brother as apprentice, Ben was just 12 years old (Russell, 1926, p.4). James used to print newspaper articles written by Ben without knowing that Ben had written them as Ben used to write them under female name (Nettleton, 2004, p. 11). When he learnt that it was Ben who was writing it, he stopped publishing them (Nettleton, 2004, p. 11). Ben was not able to carry on working with James as he argued with him a lot (Nettleton, 2004, p. 11). James was abusive (American Physics Society, n.d., para. 3) and never showed appreciation towards what Ben did. Hence, Ben ran away to Philadelphia when he was 17