Explain each character’s “role” in the following video . . .

Body Story: Body Snatchers1. Nostril Hairs2. Mucus3. Spiky Virus (Influenza B)4. Natural Killer Cells5. Macrophages6. Cilia7. Interleukins8. Fever9. Dendritic Cells10. T Cells11. B Cells12. Lymph Glands/Nodes13. Antibodies14. Memory Cells

What you will learn today . . .

• Specific immune responses target certain pathogens and involve white blood cells

• Humoral immunity is the activation of B cells to produce antibodies

• Cell-mediated immunity is the activation of T cells to produce more B cells or killer T cells

• Memory cells are the body’s way of quickly stopping a reinfection of pathogen

The Immune System

Specific Defenses

Function of the Immune System

• To fight off invading pathogens and prevent the growth of cancers

Organs of the Immune System

1. Bone marrow that produces B cells

2. Thymus gland that produces T cells

3. Lymph Nodes

4. Tonsils

5. Adenoids

6. Spleen to break down dead cells; often called “Cell Graveyard”

White Blood Cells

1. Also called lymphocytes or leukocytes

2. Typesa. T cells

b.B cells

3. Dendritic cells: a type of macrophage that recognizes and tags foreign cells as antigens; antigens are labeled differently than your own cells

Dendritic Cells:Up Close and Personal

Dendritic cells engulfing pathogen

Two types of Immunity

1. Cell-mediated

2. Humoral

3. Both immunities start with a dendritic cells engulfing the antigen, destroying the antigen, and then placing a piece of the antigen on its surface; this LABELS the macrophage with which antigen has attacked the body

Cell-Mediated Immune Response

1. Helper T cell recognizes the labeled dendritic cell and both release interleukin

2. Interleukin stimulates helper T cells, killer T cells, and suppressor T cells to rapidly divide within lymph nodes

3. T cells attack and kill all cells that have the antigen

Cell-Mediated Immunity

Humoral Immune Response

1. Interleukin stimulates B cells to divide into plasma cells

2. Plasma cells produce ANTIBODIES

3. Antibodies inactivate the antigen or mark its destruction by macrophages

4. Memory cells remain in the body to prevent reinfection by the same antigen

Humoral Immunity

How antibodies work…

Immunity

• People who are immune to a disease have either survived through the disease or have been given a vaccination

Allergies

1. Body sees harmless substances as antigens

2. Excessive release of histamines

3. Refer to “Body Story”

Autoimmune Disease

• Body attacks own cells as antigens

Hashimoto's thyroiditis Pernicious anemia Addison's disease Type I diabetes

Rheumatoid arthritis Systemic lupus erythematosus

Dermatomyositis Sjogren syndrome

Lupus erythematosus Multiple sclerosis Myasthenia gravis Reactive arthritis Grave's disease

Celiac disease - sprue

References

• http://pathmicro.med.sc.edu/ghaffar/devel-immune.gif

• http://pathmicro.med.sc.edu/ghaffar/neutrophil.jpg