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Write a comprehensive not one cancer
The multiplication of cells is so carefully regulated and responsive
to specific needs of the body, that process of cell death and birth are
balanced to produce a steady state. Sometimes the control, that regulates
the cell multiplication, breaks down. A cell in which this occurs begins
to grow body's need for further cells of its type. When such cells produce
new cells which continue to proliferate in uncontrolled fashion, an unwanted
clone of cells, called tumor is formed, which can expand indefinitely.
Tumors arise frequently, especially in older animals and humans and
are of two basic types. Some tumors are of small size and localized
(not transferred to other parts) called benign The cells in this type
usually behave like the normal cells and have little deleterious effects,
only due to either its interference with normal cells or its hormone like
secretions. and divide in unregulated fashion without In contrast,
the cells composing a malignant tumor or cancer, divide more rapidly,
mostly invade surrounding tissues, get into the body circulatory system
and set up arcas of proliferation, away from their site of original appearance.
This spread of tumor cells and establishment of secondary areas of growth
is called metastasis Cancer cells can be distinguished from normal cells
because they are less differentiated than normal cells exhibit the characteristic
of rapidly growing cells i.e. is high nucleus to cytoplasm ratio, prominent
nucleolic and may mitosis. The presence of invading cells in otherwise
normal tissue is an indication of malignancy. Cancer is caused mainly by
mutations in somatic cells. Secondary the cancer results the accumulation
of as few as three to as many as twenty mutations, in genes that regulate
cell division. These mutations bring two basic changes in the cancer cells.
First the metastatic cells break their contact with other cells and overcome
the restrictions on cell movement provided by basal lamina and other barriers
ultimately metastatic cells can invade other parts of the body. Secondly they
proliferate, unlimitedly, without minding the checks or programmes of the body.
Cancers are named according to the organ or tissue in which they arise, and
over 200 different types are recognised in humans. For simplicity they are
grouped into four categories. Carcinomas are cancers that originate in the
external or internal coverings of the body; such as the skin or lining of the
intestine. Sarcomas arise in tissues that support the body such as bone blood
forming tissues, such as bone marrow, spleen are called leukemias and that
of lymph nodes are called lymphomas Characteristic of cancer cells:
(I)Their plasma membrane and cytoplasm change and muscle.
Cancers of profoundly
(2) Cancer cells grow and divide abnormally.
(3) Cancer cells have a weakened capacity for adhesion
(4) Cancer cells are lethal.
The multiplication of cells is so carefully regulated and responsive
to specific needs of the body, that process of cell death and birth are
balanced to produce a steady state. Sometimes the control, that regulates
the cell multiplication, breaks down. A cell in which this occurs begins
to grow body's need for further cells of its type. When such cells produce
new cells which continue to proliferate in uncontrolled fashion, an unwanted
clone of cells, called tumor is formed, which can expand indefinitely.
Tumors arise frequently, especially in older animals and humans and
are of two basic types. Some tumors are of small size and localized
(not transferred to other parts) called benign The cells in this type
usually behave like the normal cells and have little deleterious effects,
only due to either its interference with normal cells or its hormone like
secretions. and divide in unregulated fashion without In contrast,
the cells composing a malignant tumor or cancer, divide more rapidly,
mostly invade surrounding tissues, get into the body circulatory system
and set up arcas of proliferation, away from their site of original appearance.
This spread of tumor cells and establishment of secondary areas of growth
is called metastasis Cancer cells can be distinguished from normal cells
because they are less differentiated than normal cells exhibit the characteristic
of rapidly growing cells i.e. is high nucleus to cytoplasm ratio, prominent
nucleolic and may mitosis. The presence of invading cells in otherwise
normal tissue is an indication of malignancy. Cancer is caused mainly by
mutations in somatic cells. Secondary the cancer results the accumulation
of as few as three to as many as twenty mutations, in genes that regulate
cell division. These mutations bring two basic changes in the cancer cells.
First the metastatic cells break their contact with other cells and overcome
the restrictions on cell movement provided by basal lamina and other barriers
ultimately metastatic cells can invade other parts of the body. Secondly they
proliferate, unlimitedly, without minding the checks or programmes of the body.
Cancers are named according to the organ or tissue in which they arise, and
over 200 different types are recognised in humans. For simplicity they are
grouped into four categories. Carcinomas are cancers that originate in the
external or internal coverings of the body; such as the skin or lining of the
intestine. Sarcomas arise in tissues that support the body such as bone blood
forming tissues, such as bone marrow, spleen are called leukemias and that
of lymph nodes are called lymphomas Characteristic of cancer cells:
(I)Their plasma membrane and cytoplasm change and muscle.
Cancers of profoundly
(2) Cancer cells grow and divide abnormally.
(3) Cancer cells have a weakened capacity for adhesion
(4) Cancer cells are lethal.
