BSC 422 Lecture Notes - Lecture 22: Cellular Differentiation, Cell Division, Gastrulation
22 May 2018
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Cancer Introduction Notes
In multicellular organisms, cell division is a normal process. Cells divide for
growth, for the development of organs, for healing of wounds and also for the
replacement of older and damaged cells. Cell division is a very complex process
which is controlled by a regulatory mechanism at both molecular and cellular
level.
When a cell of a specific tissue divides, it normally produces its own kinds of cell
of the tissue to which it belongs. It never produces the cells of other tissues.
Therefore, the process by which cells achieve this specification and specialization
is known as cellular differentiation. Differentiation of cell begins during
embryonic gastrulation stage and continues through tissue formation.
Cancer is a non-infectious disease. It starts at the molecular level of the cell and,
ultimately affects the cellular behavior. Generally, it can be defined as
uncontrolled proliferation of cells without any differentiation.
Cancer is a large class of diverse disease. All types of cancer can result from
uncontrolled cell growth and division of any of the different kinds of cells in the
body. So there are more than a hundred distinct types of cancer which vary in
their behavior and response to treatment.
The uncontrolled cell growth produces a mass of cells which are called tumors or
neoplasm tumors may be benign or malignant. A benign tumor remains confined
to its original location. They do not invade the surrounding normal tissues. They
do not spread to distant body sites.
A malignant tumor does not remain confined to its original location. They are
capable of both invading surrounding normal tissue and spreading throughout
the body via the circulatory or lymphatic systems. Malignant tumors become life-
threatening if, they spread throughout the body.
The cells of malignant tumor are derived from single cell, thus they are
monoclonal in character. Malignant tumor is composed of aberrant cells. They
behave like embryonic type, undifferentiated, having irregular, large nucleus, and
deficient of cytoplasm. Malignant tumors are generally classified into four main
types on the basis of cell type from which they arise.
Carcinomas:It includes approximately 90% of human cancer. This type is
principally derived from epithelial cells of ectoderm and endoderm. The solid
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Document Summary
In multicellular organisms, cell division is a normal process. Cells divide for growth, for the development of organs, for healing of wounds and also for the replacement of older and damaged cells. Cell division is a very complex process which is controlled by a regulatory mechanism at both molecular and cellular level. When a cell of a specific tissue divides, it normally produces its own kinds of cell of the tissue to which it belongs. It never produces the cells of other tissues. Therefore, the process by which cells achieve this specification and specialization is known as cellular differentiation. Differentiation of cell begins during embryonic gastrulation stage and continues through tissue formation. It starts at the molecular level of the cell and, ultimately affects the cellular behavior. Generally, it can be defined as uncontrolled proliferation of cells without any differentiation. Cancer is a large class of diverse disease.
