1. Immune System Pt 1
-Your skin is the first line of defense  it acts as a barrier and keeps most foreign substances out
-But nose, eyes, mouth, and ears are still vulnerable
-Defense mechanisms
for nose, eyes, mouth,
and ears include hair
and mucous

2. Immune System Pt 1
-Antigen: a protein or polysaccharide found on materials that are foreign to the body
ex: pollen, pet dander, bacteria, virus
-Pathogen: an agent that can cause disease
ex: bacteria and virus

3. Immune System Pt 1
-An example of an antigen is a surface protein of a flu virus, a protein different from any human protein
-Cells produce antibodies to oppose antigens

4. Immune System Pt 1
-The immune system rec­ognizes that the flu virus structure is different and generates proteins called antibod­ies that bind to the flu virus
-Antibodies can inactivate pathogens directly or signal immune cells that pathogens are present.

5. Life Without An Immune System
Imagine life without an immune system. Write a short story detailing what life would be like without an immune system.
In reality, there are people who live almost as if they do not have an immune system…