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Diseases and pathogens


What is a disease? It is any state of being in which one’s health is disrupted.

It’s very hard to come up with an exact definition for “disease.”

… a look through any medical dictionary soon shows that articulating a satisfactory definition of disease is surprisingly difficult. And it is not much help defining disease as the opposite of health, given that definitions of health are equally tricky…. Why is it important to know what a disease or disability is? One reason is practical: because today’s medicine has an unprecedented ability to actually do things, it matters a great deal what we decide to tackle. The ability to make powerful, effective interventions into people’s health brings with it new ethical responsibilities.

What is a disease? Jackie Leach Scully. EMBO Reports 2004 Jul; 5(7): 650–653
From Brief Review in the Living Environment, Topic 2, Disease

Syllabus (under development)

How does our immune system target invaders?

Cancers: Not one disease, but a family of diseases.

Bacteria evolving resistance to antiobiotics


High blood pressure, and a question: Are we consuming too little salt?

Impact of European plagues on Native Americans, and Americapox: The Missing Plague

Addiction is not a disease: A neuroscientist argues that it’s time to change our minds on the roots of substance abuse

Causes of disease small

What are pathogens?

from http://www.ck12.org/book/CK-12-Biology-Concepts/section/13.48/


How do we fight pathogens?

antibiotics – Only kill bacteria. Useless against all other pathogens.

anti-virals – Only kill viruses. Useless against all other pathogens.

anti-fungals – Only kill fungi. Useless against all other pathogens.

anti-protozoal – Only kill some protists. Useless against all other pathogens.

anti-helminthic – Only kill parasitic worms (helminths) . Useless against all other pathogens.



Skin is a barrier to disease

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Pin skin histamines inflammatory_response


Mental illnesses

Psychiatry is a medical field devoted to the diagnosis, study, and treatment of mental disorders.  Psychiatry


Many psychologists claim that drug and alcohol addictions are a disease. However, many scientists disagree. In this article  A neuroscientist argues that it’s time to change our minds on the roots of substance abuse.

Learning Standards

College Board Standards for College Success: Science

LSH-PE.5.4.3 Give examples, using evidence gathered from print and electronic resources, of genetic diseases (e.g., cystic fibrosis, sicklecell anemia, Tay-Sachs disease or phenylketonuria) that result from mutations to a single gene. Identify, for each example,
the specific type of mutation that causes the change in amino acid sequence and ultimately the change in the protein that is produced.

LSH-PE.5.4.4 Give examples, using evidence gathered from print and electronic resources, of instances when viruses are linked to cancer. Explain, based on knowledge of viral gene insertions and of the relationship among DNA, proteins and traits, how a viral insertion into DNA can cause cancer.

LSH-PE.5.4.5 Give examples, using evidence gathered from print and electronic resources, of the potential of using viruses for curing genetic diseases via gene therapy. Make a claim about, and justify, based on knowledge of viral DNA and viral insertions, why some viruses are appropriate for this application.

Massachusetts Comprehensive Health Curriculum Framework

Students will gain the knowledge and skills to select a diet that supports
health and reduces the risk of illness and future chronic diseases. PreK–12 Standard 4

Through the study of Prevention students will
8.1 Describe how the body fights germs and disease naturally and with medicines and
Through the study of Signs, Causes, and Treatment students will
8.2: Identify the common symptoms of illness and recognize that being responsible for individual
health means alerting caretakers to any symptoms of illness

8.5 Identify ways individuals can reduce risk factors related to communicable and chronic diseases
8.6 Describe the importance of early detection in preventing the progression of disease
Through the study of Signs, Causes, and Treatment students will
8.7 Explain the need to follow prescribed health care procedures given by parents and health care providers
8.8: Describe how to demonstrate safe care and concern toward ill and disabled persons in the family, school, and community

8.13 Explain how the immune system functions to prevent and combat disease

Interdisciplinary Learning Objectives: Disease Prevention and Control
8.a. (Law & Policy. Connects with History & Social Science: Geography and Civics &
Government) Analyze the influence of factors (such as social and economic) on the treatment and management of illness.

Benchmarks for Science Literacy, AAAS

The immune system functions to protect against microscopic organisms and foreign substances that enter from outside the body and against some cancer cells that arise within. 6C/H1*

Some allergic reactions are caused by the body’s immune responses to usually harmless environmental substances. Sometimes the immune system may attack some of the body’s own cells. 6E/H1

Some viral diseases, such as AIDS, destroy critical cells of the immune system, leaving the body unable to deal with multiple infection agents and cancerous cells. 6E/H4

Vaccines induce the body to build immunity to a disease without actually causing the disease itself. 6E/M7** (BSL)

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