The Nature of Disease p98

Chapter 39.1

P98 Nature of Disease:

Warm up: Have you ever had an infection? Describe what it was like.

Disease: a change that disrupts the normal functioning of the body

Infectious Disease: caused by the presence of pathogens in the body.

Pathogens can be: Bacteria, Protozoans, Fungi, Viruses, Parasites

P 98 Sources of Pathogens

Soil Contaminated water Infected animals Other people

Some diseases are inherited from DNA and are not contagious: Hemophilia Sickle Cell Anemia

P 98 4 Ways Pathogens are transmitted:

Direct contact:

skin, body fluids

By an object:

Food poisoning

Through the Air:

dust particles

By an intermediate organism (vector):Malaria – mosquitoes

Patterns of Disease p98

Epidemic – a disease that found among many people in an area: Bird flu, SARS (Asia) Mad cow (England) Ebola (Africa)

Pandemic – a global epidemic Influenza HIV-AIDS

Treatments: Antibiotics –will kill or inhibit the

growth of fungus or bacteria.

With misuse, bacteria will become resistant to them!

DO NOT AFFECT VIRUSES!

Defense Against Infectious Diseases p100

Chapter 39.2

P 100 Homeostasis

Stress Lack of sleep Alcohol use Drug use Smoking Dehydration Unhealthy diet

Disrupt Homeostasis and prevent your body from fighting off disease.

Warm up: What are things you can do to stay healthy?

Homeostasis: When the body is well and working properly

Maintaining Homeostasis p100

Lymphatic System Cleanses the cells of

pathogens and carries them out of the body.

The lymph glands collect the “dirty” fluid and filter it.

Ex: Tonsils

Innate Immunity p100

1st line of defense against pathogens Skin: Creates a physical barrier Body secretions

Mucus Sweat Tears Saliva

have the enzyme lysozyme that kills some bacteria

Innate Immunity Cells p100

When a pathogen invades or an area is injured, inflammation occurs to bring fluids to area.

Phagocytes: white blood cells that surround and kill pathogens

Macrophages: white blood cells that are first responders to defend tissue, “big eaters”

Interferons: proteins that protect cells against viruses by making cells produce antiviral proteins.

Pus: a collection of live and dead white blood cells and pathogens that collect at the infected site.

Acquired(Adaptive) Immunity p102Warm up: explain what innate immunity is

and give 2 exmples. When our White Blood Cells get attacked

by a pathogen, they make antibodies for them while they fight them off.

These stay in our bodies and alerts the immune system to kill off the pathogen if it ever comes back.

Acquired Immunity cells p 102

Antigens are markers on foreign bodies that are recognized by our lymphatic system.

At lymph nodes, lymphocytes will recognize and kill foreign body.

In blood, Helper T cells can bind to macrophages to help it recognize and bind to pathogen to kill it.

B cells in blood bind to T cells and become plasma cells that make more antibodies that help to remember the pathogen so it can kill it faster next time.

Cytotoxic T cells can also kill pathogens.

Passive Acquired Immunity p102

Acquiring antibodies made by someone else: From the mother to baby

through the placenta &milk

Vaccines – injection of weakened pathogens so your immune system can make antibodies.