Immune response to infectious diseases Flashcards
What is the immune system’s job?
Protect the body from infections.
What are the two main types of immunity?
Innate (fast, non-specific) and adaptive (slow, specific).
What is the first line of defense?
Skin, mucus, stomach acid, and other barriers.
What is the second line of defense?
Inflammation, fever, and immune cells like macrophages.
What is the third line of defense?
Adaptive immunity (B cells & T cells).
What immune cells are in innate immunity?
Macrophages, neutrophils, natural killer (NK) cells.
What immune cells are in adaptive immunity?
B cells and T cells.
What do macrophages do?
Eat (phagocytose) pathogens and present antigens.
What do neutrophils do?
First responders; attack bacteria.
What do natural killer (NK) cells do?
Kill virus-infected and cancer cells.
What is inflammation?
Swelling, redness, heat, pain—body’s response to infection.
Why does fever help fight infection?
Increases immune cell activity, slows pathogen growth.
What do B cells do?
Make antibodies to fight infections.
What do T cells do?
Kill infected cells (Cytotoxic T) & help other immune cells (Helper T).
What are antibodies?
Proteins that bind to pathogens for destruction
What are the five types of antibodies?
IgG, IgA, IgM, IgE, IgD.
How do antibodies fight infections?
Neutralization, opsonization, complement activation.
What is immunological memory?
The immune system remembers past infections for faster response.
How do vaccines work?
Train the immune system to recognize pathogens.
What is a primary immune response?
First time the body fights an infection (slower).
What is a secondary immune response?
Faster and stronger response due to memory cells.
What is passive immunity?
Receiving antibodies (e.g., from mother’s milk or injections).
What is active immunity?
Body makes its own immune response (e.g., infection or vaccine).
What is an autoimmune disease?
When the immune system attacks the body (e.g., lupus, type 1 diabetes).
What is an allergy?
Overreaction of the immune system to harmless substances.
What is immunodeficiency?
A weakened immune system (e.g., HIV, SCID).
What is the role of cytokines?
Signaling proteins that help immune cells communicate.
What is the complement system?
Proteins that help kill pathogens.
How does the immune system recognize pathogens?
By detecting antigens on the pathogen’s surface.
