Week 12 Flashcards
(28 cards)
What is the adaptive immune response?
The adaptive immune response is specific, targeting specific antigens and coordinating the immune system’s response to pathogens.
What is the role of B cells in adaptive immunity?
B cells are responsible for humoral immunity and produce antibodies that bind to specific antigens on pathogens, helping neutralize, tag, or eliminate foreign invaders.
What is humoral immunity?
Humoral immunity deals with pathogens in body fluids (blood, lymph), not inside cells. It involves antigens and antibodies.
What are antigens?
foreign substances (such as pathogens, viruses, and toxins) that trigger an immune response.
What are antibodies?
Antibodies (also known as immunoglobulins) are proteins made by B cells that bind specifically to antigens to neutralize or mark them for destruction.
What happens during the primary immune response?
occurs during the first exposure to an antigen, where plasma cells produce antibodies (mainly IgM) and memory B cells are created, but remain inactive.
What happens during the secondary immune response?
occurs with later exposures to the same antigen, it is faster and stronger due to the presence of memory B cells. More antibodies (mainly IgG) are produced quickly after class switching.
What are the components of antibody structure?
consist of two identical light chains and two identical heavy chains, which both contribute to the antigen-binding sites.
The heavy chains form the Fc region, which binds to immune cells.
What are the 5 classes of antibodies?
- IgG: Abundant in blood and extracellular fluid, crucial for long-term immunity and secondary response.
- IgA: Found in secretions (tears, saliva, mucus, breast milk).
- IgM: First antibody produced during primary response.
- IgE: Involved in allergic reactions and parasitic defense.
- IgD: Found mostly on naïve B cell membranes, rarely secreted.
How do antibodies help the immune system?
neutralize pathogens, opsonize pathogens (mark them for phagocytosis), and activate complement systems to enhance pathogen destruction.
What is cell-mediated immunity?
involves cytotoxic T cells that destroy infected cells, with helper T cells activating B cells and macrophages to enhance the immune response.
What is the role of cytokines in immunity?
secreted by helper T cells help coordinate the immune response by guiding the activation of B cells and cytotoxic T cells.
What are memory T cells?
formed during an immune response and provide faster responses during subsequent encounters with the same pathogen.
What are hypersensitivity reactions?
occur when the immune system overreacts, causing harm to the body and leading to conditions such as allergies and autoimmune diseases.
What are the 4 types of hypersensitivity reactions?
Type I (Immediate): Involves allergens and leads to allergic reactions.
Type II (Cytotoxic): Involves the body’s own cells and causes damage.
Type III (Immune Complex-Mediated): Involves immune complexes causing inflammation.
Type IV (Delayed): Occurs 24–72 hours after exposure, involving macrophages and T cells causing tissue damage.
What is Type I hypersensitivity?
an immediate allergic reaction that involves IgE antibodies binding to mast cells, triggering the release of histamine and causing symptoms like asthma and hay fever
What are the common symptoms of allergies in Type I hypersensitivity?
bronchial constriction, intestinal muscle constriction, vasodilation, and increased capillary permeability, leading to tissue swelling and inflammation.
What is immune dysregulation?
occurs when the immune system’s response is unbalanced, leading to diseases such as autoimmune diseases or conditions like COVID-19, where dysregulated immune responses worsen tissue damage.
What are immunization and its purpose?
stimulates immunological memory without causing disease, preparing the immune system for future exposure to pathogens by creating a faster and stronger response.
What is the basis for vaccine effectiveness?
Immunological memory is the basis for vaccine effectiveness, allowing the body to respond faster and more effectively when re-exposed to the same pathogen.
What is the difference between active and passive immunity?
Active immunity: Protection produced by an individual’s own immune system, resulting in memory and long-term protection.
Passive immunity: Protection acquired through the transfer of antibodies from another individual, providing short-term protection without memory.
What is the role of booster doses in vaccination?
Booster doses act as reminders to the immune system, reactivating memory cells and strengthening immunity against specific pathogens.
What are the types of vaccines?
Toxoids: Inactivated bacterial toxins.
Live Attenuated: Weakened pathogens that mimic natural infection.
Subunit/Polysaccharide: Antigens linked to proteins to improve immune response.
Inactivated (Killed): Killed pathogens or parts of them.
Recombinant (Genetically Engineered): Antigens produced through genetic engineering.
What is the seasonal influenza vaccine?
contains HA (Hemagglutinin) and NA (Neuraminidase) proteins to prevent infection by blocking viral entry and release.
