Environmental Influences on Tumor Development and Spread Essay

Environmental Influences on Tumor Development and Spread - Essay ExampleBasic diagnostic of malignant tumors is the abnormality in the cells, which is expressed through a decreased control of return and functions, causing fatal diseases in the patients with invasive growth and metastasis. The disagreement of tumors is based on the following criteria histogenesis of the tumors, histological image, biological activities of the tumor, eponyms and anatomy of the tumors (Abeloff et al.).According to their histogenesis, tumors are classified as epithelial and mesenhimal. However, such classification is incomplete, as received tumors origins is hard to indentify, such as melanomas and ovarian tumors, or cells which usually are not fond in the adult organism, such as embryonic tumors.The histologic image divides the tumors into a strong, middle or weak differentiation, depending on the maturity of the cells. If there is a complete loss of identity of the tumor in similitude to the wave r that the tumor is generated from, we call that undifferentiated and anaplastic.The most important and familiar division of tumors is according to their biological activities. They are divided into auspicious and malignant benign tumor cells are very similar to the cells of the tissue they originate from and they are very well differentiated. They grow slowly with expansion and the tumor is usually encapsulated. malignant tumors get to non-differentiated cells and are characterized with progressive growth and infiltration in surrounding tissue. In time, malignant cells enter into the blood and lymph vessels and through them they arrive to other separate of the organism where they cause metastasis or secondary growth.(Jovanovski et al.) There are tumors with semi-malignant behavior, which are usually represent locally malignant. In this group of tumors a localized growth is emphasized, while foreign metastasis appear extremely rare.Some tumors are named according to the authors th at described them, for example Wilmsov, Hodgkin lymphoma, Brenner and other. Other tumors are named according to the organ, and not according to the tissue from which the originate, for example, hepatoma.The development of malignancyMalignant tumors can develop from any other tissue or organ, at any age. Before analysis of the growth and scattering of the malignant tumors, a review of cell kinetics is necessary, in particular, division of the cells. All human cells which are capable to divide (bone marrow, gastrointestinal tract) enter in a cell cps, which consists of 4 phases G0 or resting phase, when the cells do not proliferate G1 or intermittent before the DNA synthetic phase (last from 12 hours to some(prenominal) days) S phase or synthesis of DNA which lasts from 2 to 4 hours G2 phase or phase after DNA synthesis, which lasts 2 to 4 days, and the cells have a tetraploid amount of DNA and M1 phase or mitosis, which lasts from 1 to 2 hours (Abeloff et al).The new daughter-cel ls either enter in a G0 phase or mother a new cell cycle. Primary malignant tumors will arise with malignant change of one or more cells during suitable conditions. Cells that enter into a continuous division will create several cells that gather and create a primary tumor mass. Malignant cells usually have a cycle that last for several days. Generational time is the time necessary for a malignant cell to enter into a cell cycle and to create two