Transcript Nerve activates contraction

PowerPoint® Lecture Slide Presentation by Robert J. Sullivan, Marist College
Human Biology
Concepts and Current Issues
Second Edition
MICHAEL D. JOHNSON
CHAPTER 18
CANCER: UNCONTROLLED
CELL DIVISION AND
DIFFERENTIATION
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Characteristics of Benign Tumors and
Cancers
Table 18.1
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Tumors
• Benign
• Remain in one location
• Single, well defined mass
• May be surrounded by connective tissue
• Cancerous
• Abnormal cell structure, may appear
undifferentiated
• May spread
• Edge of tumor not clearly defined
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Malignant Tumor Development
Figure 18.2
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Cancerous Cells: Lose Control Over
Cell Functions
• Dysplasia: abnormal change in cell structure
• In Situ Cancer: malignant tumor in only one
place
• Matastases: secondary tumors at other locations
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
How Cancer Develops
• Mutated or damaged genes
• Proto-oncogenes: normal regulatory genes
• Oncogenes: mutated or damaged proto-oncogenes
• Tumor suppressor genes: regulatory genes repress
cell growth, division, differentiation, adhesion
• May be turned off, damaged or mutated in cancers
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Carcinogens
Table 18.2
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Advances in Diagnosis:
Early Detection
• Tumor imaging: X-rays, PET, MRI
• Genetic testing: identify mutated genes, privacy
and treatment issues
• Enzyme tests for cancer markers: screening large
numbers of people
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Cancer Treatments
• Conventional treatments: surgery, radiation, and
chemotherapy
• Immunotherapy: promotes the immune response
• Starving cancers: inhibits angiogenesis
• Molecular treatments: target oncogenes
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Ten Most Common Cancers
Table 18.3
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Most Common Cancers
• Skin cancer: three major types
• Breast cancer: almost exclusively in women
• Prostate cancer: most common after age 50 in
males
• Lung cancer: smoking is the leading risk factor
• Cancers of colon and rectum: early detection has
increased survival rates to 62%
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Most Common Cancers
(cont.)
• Lymphoma: related to altered immune function
• Urinary bladder cancer: surgery needed early
• Cancer of the uterus: includes cervical cancer
and cancer of the endometrium
• Leukemia: chemotherapy often effective
• Cancers of mouth and pharynx: tobacco major
risk
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.
Most Cancers are Preventable
• Know family history
• Get regular medical screenings
• Learn self-examination techniques
• Avoid direct sunlight 10 AM to 4 PM, avoid
sunlamps and tanning salons
• Watch diet and weight
• Don’t smoke
• Drink in moderation, if at all
• Be informed
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings.