Disorders of the Immune System Flashcards
What is innate immunity?
Your built-in, non-specific immune defense!
Includes skin, stomach acid, tears, and mucus. Macrophages (WBCs) eat invaders and release chemical signals to call for backup!
What do natural killer (NK) cells do?
Destroy infected & cancerous cells BEFORE your body even realizes they’re a problem!
What’s the difference between innate and adaptive immunity?
✔️ Innate = First responder, fast, non-specific (like police 🚔).
✔️ Adaptive = Learns & remembers, highly specific (like detectives 🕵️♂️).
What are the two main types of adaptive immunity?
1️⃣ Cell-mediated immunity (T cells) → Fights viruses & infected cells.
2️⃣ Humoral immunity (B cells) → Produces antibodies to attack invaders.
What do CD4 and CD8 T cells do?
• CD4 (Helper T cells) = “Team captains” that direct the immune response.
• CD8 (Cytotoxic T cells) = “Assassins” that kill infected cells.
What are antigen-presenting cells (APCs)?
Macrophages & dendritic cells that show immune cells what to attack!
What do plasma cells (activated B cells) do?
Make antibodies (immunoglobulins, Igs)!
What are the 5 types of antibodies (Igs)?
🛡️ IgM – First responder in infections.
🛡️ IgG – Long-term immunity (memory cells).
🛡️ IgA – Found in saliva, tears, breast milk.
🛡️ IgE – Allergy response! (Histamine release).
🛡️ IgD – Function not well understood (rare).
What do vaccines do?
Expose your body to a weakened form of a pathogen so you develop immunity without getting sick!
What’s a booster shot?
A second dose to remind your immune system how to fight the pathogen.
What’s a toxoid vaccine?
Protects against toxins made by bacteria (Example: Tetanus vaccine).
What’s the difference between active & passive immunity?
✔️ Active immunity = You MAKE antibodies (from infection or vaccine). Long-lasting!
✔️ Passive immunity = You RECEIVE pre-made antibodies (breast milk, antibody injections). Short-term!
What are the 4 types of hypersensitivity reactions?
1️⃣ Type I (Immediate/Allergic) – IgE, causes anaphylaxis, asthma, hay fever.
2️⃣ Type II (Cytotoxic) – Antibodies attack cells (Example: Blood transfusion reaction!).
3️⃣ Type III (Immune Complex) – Antigen-antibody clumps cause tissue damage (Example: Lupus, RA).
4️⃣ Type IV (Delayed) – T cells attack days later (Example: Poison ivy, TB test, transplant rejection).
What happens in anaphylaxis?
Severe allergic reaction → airway swelling → needs epinephrine (EpiPen) fast! 🚑
What is an autoimmune disease?
Your immune system attacks your own cells by mistake. 😱
What is molecular mimicry?
Your body confuses self-cells with an infection and attacks them. (Example: Rheumatic fever after strep throat!)
What are examples of autoimmune diseases?
✔️ Lupus (SLE) – Attacks skin, joints, kidneys (butterfly rash).
✔️ Rheumatoid Arthritis (RA) – Attacks joints, causing inflammation & pain.
What’s the difference between primary vs. secondary immunodeficiency?
✔️ Primary = Born with it (SCID – Bubble Boy Syndrome).
✔️ Secondary = Develops later (HIV/AIDS, chemotherapy).
What happens in Severe Combined Immunodeficiency (SCID)?
No T or B cells = No immune defense!
• Without treatment, kids die within 2 years.
• Bone marrow transplant = only cure!
What is DiGeorge Syndrome?
T cells don’t develop properly due to missing thymus. 🧬
What does HIV attack?
CD4 (Helper T) cells → Weakens immune system → Opportunistic infections!
What are the 3 stages of HIV?
1️⃣ Acute stage – Flu-like symptoms, contagious.
2️⃣ Chronic stage – HIV is in the body but no major symptoms yet.
3️⃣ AIDS – CD4 count below 200, high risk of infections.
How does HIV spread?
• Sexual contact (semen, vaginal fluids).
• Blood-to-blood contact (needles, transfusions).
• Mother to baby (pregnancy, breast milk).
What’s the most accurate early test for HIV?
HIV RNA assay (detects viral load BEFORE antibodies appear).
What is ART (antiretroviral therapy)?
Combination of meds that suppress HIV but don’t cure it.
• Includes reverse transcriptase inhibitors, protease inhibitors, and fusion inhibitors.
What is PrEP (Pre-Exposure Prophylaxis)?
Medication (Truvada) taken to prevent HIV before exposure!
