Non-specific imm
What are valves?
These structures inside collecting lymphatic vessels prevent backward flow.
What are lymph nodes?
These small, bean-shaped organs filter lymph along lymphatic vessels.
What is adaptive, or specific, immunity?
Defense directed against particular antigens that develops after exposure and produces immune memory.
What type of immunity provides a rapid, general defense without needing previous exposure?
Answer: Innate immunity.
An exaggerated or inappropriate immune response that can damage tissues.
Hypersensitivity
What is skin?
This physical barrier covers the body and helps prevent pathogens from entering.
What are natural killer (NK) cells?
These innate immune cells kill virus-infected cells and some cancer cells.
Which type of adaptive immunity uses T cells to coordinate defenses and destroy infected cells?
Cell-mediated immunity.
Which type of adaptive immunity uses antibodies made by plasma cells?
Antibody-mediated, or humoral, immunity.
Disorders caused when the immune system mistakenly attacks the body's own cells and tissues.
autoimmune disorders
What is the complement system?
This group of blood proteins enhances inflammation, coats pathogens to help phagocytes recognize them, and can rupture some microbes.
Name the four cardinal signs of inflammation.
redness, heat, swelling, and pain?
Q1:What do activated B cells become?
Q2 How do helper T cells help activate B cells?
A1: Plasma cells that secrete antibodies and memory B cells that support future responses.
A2: They recognize antigen presented by the B cell on MHC II and provide activating signals, including cytokines.
What four protein chains make up a typical antibody?
Answer: Two identical heavy chains and two identical light chains.
A severe, rapid, potentially life-threatening allergic reaction affecting the whole body.
anaphylaxis
These proteins released by virus-infected cells help nearby cells resist viral infection.
interferons
Where are the spleen, thymus, and tonsils located, and what does each do?
What does a B cell’s receptor recognize and bind?
Answer: A specific antigen.
Name four ways antibodies help defend the body.
Answer: Neutralization, agglutination, opsonization, and complement activation.
A transplant between genetically identical individuals, such as identical twins.
isograft
Explain how increased blood flow and increased vessel permeability help defend an injured tissue
Increased blood flow brings more defense cells and substances to the area. Increased permeability allows fluid and protective proteins to enter the tissue; white blood cells also leave the bloodstream to attack pathogens and clear debris.
Put these events in order: phagocytes arrive; tissue is injured or invaded; pathogens and debris are cleared; inflammatory chemicals are released; blood vessels dilate and become more permeable.
injury/invasion → chemical release → vessel dilation and increased permeability → phagocyte arrival → clearance
Describe the usual steps of B-cell activation for a protein antigen.
Antigen binds the B-cell receptor → the B cell takes it in and presents a fragment on MHC II → a helper T cell provides activating signals → the B cell multiplies and forms plasma cells and memory B cells.
What is an antigen-antibody complex, and how can its formation help eliminate a threat?
Answer: It forms when an antibody binds its antigen. This can block the antigen’s effects or mark it for removal by phagocytes or complement.
An autoimmune disease affecting communication between nerves and skeletal muscles, causing muscle weakness.
Myasthenia Gravis