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Name the basic kinds of tissue growth changes.

Neoplasia

 

Name the basic kinds of tissue growth changes.

Two kinds of tissue growth changes are distinguished: hyperbiotical and hypobiotical processes. To the first group belongs: a) hypertrophy and hyperplasia; b) regeneration; c) Neoplasia (tumour). To the second - an atrophy; a dystrophy and a degeneration.

 

16.2. What is the neoplasia process? What kinds of tumoursdoexist?

Neoplasia process is a typical pathological process which essence is an unlimited, noncontrollable growth of the tissue which hasn?t been connected with the general structure of the injured organ and its functions.

There are two kinds of tumours exist: benign and malignant.

16.3. Why tumoral process is considered to be the general biological phenomenon?

Tumoral process has the general biological character because tumours arise both at animals, and at plants. Tumours are found at all kinds of multicellular alive organisms (at insects, fishes, amphibians, reptiles, mammals).

 

16.4. Are there features in character of tumoral process in humans and different kinds of animals?

In humans 90 % of all malignant tumours have an epithelial origin, so are cancer. At the same time at large horned livestock, horses, pigs 80 % of malignant tumours occur from blood cells, so are hemoblastoses, and at dogs 50 % of malignant new growths are represented as sarcomas - a tumour of a connective tissue cells.

 

16.5. What are the basic distinctions between benign and malignant tumours?

1. Benign tumours consist of well differentiated cells. These tumours keep typical structure of a tissue which they have occurred from. At the same time malignant tumours are characterized by loss of a differentiation of cells, simplification and atypical structures.

2. Benign tumours often grow slowly; their growth can stop, and sometimes also observed return development (regression). The malignant tumours are characterised by fast growth which does not stop spontaneously. Spontaneous regress of such tumours is unknown.

3. Benign tumours have a capsule and grow expansively, so they do not sprout in surrounding healthy tissues, but move apart them. Growth of malignant tumours is invasive (infiltrative). They have no capsule and sprout in surrounding tissues.

4. Benign tumours do not give metastases while malignant usually give metastasises.

5. Benign tumours are well treated by the surgical treatment, and lethal outcomes, do not happen as a rule. Malignant tumours at absence of treatment lead to death.

 

16.6. What are methods of experimental studying of tumours?

There are such methods of experimental modelling of tumours as the induction, transplantation and an explantation.

The method of an induction provides reproduction of malignant tumours by introduction of carcinogenic factors in an organism. More often with this purpose chemical carcinogenic substances and out of cells filtrates of a tumoral tissue containing oncogenic viruses are used. Besides with the purpose of an induction of tumours physical influences (x-ray radiation, radioactive participles, ultra-violet radiation) are sometimes used.



The transplantation method is reinoculation of tumours from one animal to another. For the first time it was carried out by M. Novinskiy in 1876. For successful transplantation of a tumour following conditions are important: a) transplantation should be carried out between the individuals of one kind of animals; b) alive viable tumoral cells should be intertwined; c) transplantation should be made in sterile conditions in order to prevent inflammatory process in a tissue.

The method of an explantation is a cultivation of a tumour in a culture of tissue outside of an organism. This method enables to study influence of various factors on tumoral growth, to carry out the search of methods of therapy of malignant tumours.

 


Date: 2016-06-12; view: 101


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