CHAPTER 17 SECTION 8
By Andrew Stegenga, Fabian Rodriguez, Marlon Loyola, Micheal
Kouzmanov
INTRO
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Millions today are fighting battles with cancer, unlike in the past where a future with
cancer was bleak. But unfortunately, preventing cancer is far easier that curing it.
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Most cancers result from conditions in peoples lives. For example lung cancer cases
occur in people who smoke.
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There are over one-hundred diseases labeled as cancer, each have different names
based on its location in the body. Some are named for the tissues they corrupt with the
suffix –oma meaning tumor added on.
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Cancers of the immune system - lymphomas
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Cancers of blood-forming organs - leukemias
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Cancers of the glands and body linings, like the skin or the lining of the digestive tract, carcinomas.
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Cancers of connective tissue, including bones, ligaments, and muscles, - sarcomas
DEVELOPMENT OF CANCER
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Cancer begins with a change in normal cells.
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After change cell response accelerates far out of control.
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Steps of development 1) Exposure to a carcinogen
2) Entry of the initiator(carcinogen) into a cell
3) Change of the cells genetic material. The change may be a mutation.
4) Possible speeding up of cancer formation by a promoter
5) Out-of-control multiplication of the cells
6) Tumor of other malignancy formation.
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All of the danger of cancer lies within a persons cells, so cancer itself is not contagious to other
people, but once a cancer forms it can spread to many parts of the body.
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Unlike normal cells, cancer cells cannot stop dividing and multiplying. This results in a tumor of
cancerous cells.
HARMLESS AND CANCEROUS TUMORS
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A benign is a harmless tumor. It does not spread, it is well defined, and it is a solid mass
in and external membrane.
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Cancerous tumors are malignant. They present a threat to health. If a cancerous tumor
gains in size it competes with normal tissue’s oxygen and space.
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With time cancer interrupts normal function of tissues organs. For example the tumor may
block the intestinal contents. In cancer of the brain the growing tumor threatens thought
processes and control of body.
TUMORS- THE SPREAD OF CANCER
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In addition to invading adjacent tissues cancerous cells brake off from original site and
ride body fluids to colonize new areas.
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Beginning of cancer only sheds a few cells. The larger it gets the more cells shed off to
find different areas to contaminate in other areas of the body. At this point it is said that
the cancer has metastasized.
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Cancer causes death when it interrupts the functioning of vital organs such as the bloodbuilding organs, lungs, or brain.
TUMORS- THE ROLE OF THE IMMUNE SYSTEM
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Immune system watches for escaped cancer cells. The system works to stop these
dangerous travelers before they lodge themselves in new, important tissues.
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It can only catch a certain number of cancer cells at any time. When a the immune
defenses fail, that is when cancer treatment is needed.
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The success of treatment depends on whether or not it gets under way before the cancer
cell has metastasized.
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After the initiating event some cancers take as long as 20 years to develop.
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Because of this it is very difficult for doctors to find the causes of these cancers.
VOCAB
1)
Cancer- a disease in which abnormal cells multiply out of control, spread into surrounding tissue and other body
parts and disrupt normal functioning of one or more organs.
2)
Tumor- an abnormal mass of tissue that can live and reproduce itself, but performs no service to the body
3)
Malignancy- a dangerous cancerous growth that sheds cells into body fluids and spreads to new locations to start
new cancer colonies
4)
Melanoma- an especially dangerous cancer of the pigmented cells of the skin, related to sun exposure in people
with light colored-skin
5)
Myeloma- a cancer originating in the cells of bone marrow
6)
Lymphomas- cancers that arise in organs of the immune system
7)
Leukemia- cancers that arise in the blood cell-making tissue
8)
Carcinomas- cancers that arise in the skin, body chamber linings, or glands
9)
Sarcomas- cancers that arise in the connective tissue cells, including bones, ligaments, and muscles
10) Initiator- a carcinogen, an agent required to start the formation of cancer
11) Mutation- a change in cell’s genetic material. Once the genetic material has changed, the change is inherited by the
offspring of that cell
12) Promoter- a substance that assists in the development of malignant tumors, but does not initiate them on its own
13) Benign- noncancerous, not harmful; a description of a tumor that is not able to spread from one area to another
14) Metastasized- when speaking of cancer cells, a term that means the cancer cells have migrated from one part of the
body to another,, and started new growths just like the original tumor
CITATION
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Webb, Frances. Health Making Life Choice. Second. Illinois: NTC, 2000. 812. Print.