The Immune System Questions

2. What is the body's second line of defense? When does it take effect?

-The body's second line of defense includes the inflammatory response and phagocytosis by nonspecific leukocytes. The defense attacks pathogens that manage to enter the body. It takes effect after the first part fails. When a body part get's cut, it releases special types of chemicals.

1. Identify three types of barriers in the body's first line of defense. Give an example of each type of barrier.

- 1. Mechanical- mucus - 2. Chemical- Low Ph - 3. Biological- bacteria on human skin

What are antigens, and how do lymphocytes "recognize" them?

- Antigens are molecules that the immune system recognizes as foreign to the body. Lymphocytes recognize antigens by receptor molecules they have on their surface. Those molecules bind only with particular antigens.

5. What is immunity? What role do memory cells play in immunity?

- Immunity: Being able to resist a pathogen. Memory cells are long living plasma cells that remember the shape and form of viruses.

1. What's the difference between an autoimmune disorder and an immunodeficiency disorder?

- Immunodeficiency happens when the immune system is not working properly (it cannot fight off pathogens that a normal immune system would be able to resist) while autoimmune diseases occur when the immune system fails to recognize the body's own molecules as belonging to the person (it instead attacks the body cells as if it were dangerous pathogens).

4. Describe one way that cytotoxic T cells destroy cells infected with viruses.

- The T cell releases proteins that form pores in the membrane of the infected cell

. List three parts of the lymphatic system and their functions.

1. Organs: an example is bone marrow which produces all lymphocytes - 2. Lymph vessels: Circulate lymph - 3. Lymph nodes: Filter out small structures

3. How do plasma cells form, and how do they help fight pathogens?

B cells are activated by antigens, which attract a helper T- cell that tells the B cell to develop into a plasma cell. B cells must be activated by an antigen before it can fight pathogens. (The b cell develops into a plasma cell.)

3. Identify the roles of nonspecific leukocytes in the body's second line of defense.

Nonspecific leukocytes role is to fight infections and get ride of debris.

5. What is nonspecific defense?

Nonspecific defense is the response of leukocytes. It is the same no matter what type of pathogen is involved. An example is phagocytosis.

4. State how phagocytosis helps defend the body from pathogens.

Phagocytes eat up pathogens.