Cancer :: essays research papers fc

I chose to do my report on apprizecer because it is a subject I want tolearn about and because it can probably fit 5 pages. Mybibliography is on the ending of the report, my teacher helped mewith it because I didnt know how to do it. Cancer is the name fortumors that are malignant. Malignant tumors do non respond tobody mechanisms that limit growing. Malignant tumors show a notnormal cell structure the same functional specialized cells. Also crab nerve center cells growing in laboratory tissue culture do not stopgrowing when they touch each other on a internal-combustion engine or other solidsurface but grow in masses several layers deep they are said to lackcontact inhibition. freeing of contact inhibition accounts for two othercharacteristics of cancer cells invasiveness of surrounding tissuesand metastasis spreading via the lymph system or blood to othertissues and organs. Cells are typically controlled by yield factorscompetence factors that stimulate cells to enter the b eginning phaseof cell replication and progression factors that insure completion ofthe replication cycle. The unrestricted growth rates of cells are dueto the activation and lack of inhibition of oncogenes. They arecancer causing genes.Cancer tissue that grows without limits competes with normaltissue for nutrients kills the normal cells by nutritional deprivation.cancerous tissue also causes secondary effects with the symptomsof a malignant growth caused by the pressure of the growing tumoragainst surrounding tissue or the metastasis of cancer cells andtheir invasion of other organs. Cancers are graded as to degree ofmalignancy on a scale of one through four the distinction amongsteven benign and malignant neoplasms is obscure. All organs andtissues are susceptible to cancer.A lot of human cancers may be caused or at least triggered byvarious chemical agents. Alkylating agents are thought to have acarcinogenic effect because they chemically alter the cells nucleicacids. Nitrites c ommon additives in processed meat react withamines in the stomach to form nitrosoamines which someauthorities believe may be carcinogenic to humans. Othercommonly occurring carcinogens are azo dyes, polycyclichydrocarbons, and urethane. true carcinogens presentoccupational hazards. Asbestos particles once inhaled stay in thelung and act as an irritant. In the asbestos and constructionindustries workers have a high probability of developing a fatalcancer of the chest lining or abdominal lining 25 to 30 years afterthe initial inhalation of . Asbestos also has been united to lung andcolon cancers in exposed individuals. Oral cancer common in Indiais commonly attributed to the chewing of betel nuts. Although theapparently increasing incidence of some types of super malignant