Ch 18 Immune System lecture Flashcards
What is immunity?
The ability to destroy pathogens and prevent infection.
What are the components of the immune system?
Lymphoid organs, lymphocytes, WBCs, and immune chemicals.
What is the function of the lymphatic system?
It returns lymph to circulation and helps filter pathogens.
Where are lymphocytes produced?
Red bone marrow.
What is the primary function of lymph nodes?
Filter pathogens and activate immune responses.
What is the spleen’s role in immunity?
It filters blood, destroys old RBCs, and stores platelets.
What is the function of the thymus?
It matures T cells for immune function.
What are antigens?
Chemical markers that identify cells as “self” or “foreign.”
What are natural killer (NK) cells?
Lymphocytes that destroy infected or cancerous cells using cytolysis.
What are the two main types of lymphocytes?
T cells and B cells.
Where do T cells mature?
In the thymus.
What is the main function of T cells?
Direct attack on infected or abnormal cells.
Where do B cells mature?
In the bone marrow.
What is the role of B cells?
They produce antibodies to fight infections.
What are antibodies?
Immunoglobulins (Ig) produced by plasma cells in response to antigens.
What are the five classes of immunoglobulins (Ig)?
IgG, IgA, IgM, IgE, IgD.
What is the function of IgG?
Provides long-term immunity; most abundant antibody.
Where is IgA found?
Mucosal secretions (tears, saliva, breast milk).
What is the function of IgM?
First antibody produced in an immune response.
Which antibody is involved in allergic reactions?
IgE.
What is the role of IgD?
Involved in B cell activation.
What is cell-mediated immunity?
An immune response that involves T cells attacking infected cells.
Which cells are involved in cell-mediated immunity?
Cytotoxic T cells, helper T cells, and memory T cells.
What is humoral immunity?
Immunity mediated by antibodies produced by B cells.
What is an antigen-antibody complex?
A structure that marks pathogens for destruction.
What is the complement cascade?
A protein cascade that helps destroy pathogens and attract macrophages.
What happens during a first antigen exposure?
Slow antibody production and memory cell formation.
What happens during a second antigen exposure?
Rapid antibody response due to memory cells.
What is the purpose of vaccines?
To stimulate the immune system and create memory cells.
How do vaccines prevent viral infections?
They neutralize viruses before they can enter cells.
What is the role of IgE in allergic reactions?
It binds to allergens and triggers histamine release.
What is passive immunity?
Immunity acquired from external antibodies.
What are examples of passive immunity?
Antibodies from mother to baby (placenta/breast milk) or an injection (e.g., Hepatitis B immunoglobulin).
Is passive immunity temporary or long-lasting?
Temporary.
What is active immunity?
Immunity developed by producing antibodies after infection or vaccination.
What are examples of active immunity?
Immunity after infection (natural) or after vaccination (artificial).
What is a CBC with differential?
A lab test measuring WBC types and immune function.
What is an ESR test?
Erythrocyte Sedimentation Rate; detects inflammation.
What does a high CRP level indicate?
Inflammation or infection.
What is the purpose of a rheumatoid factor (RF) test?
To diagnose autoimmune diseases like rheumatoid arthritis.
What are antigen-antibody immunoassays used for?
To detect infections and immune conditions.
What is the purpose of HIV nucleic acid testing?
To confirm HIV infection.
What is the function of CD4 and CD8 tests?
To evaluate immune function, especially in HIV patients.
What is genetic testing used for in immunology?
To detect genetic immune disorders.
What is a skin test used for?
To diagnose allergies or infections like tuberculosis.
What is an example of a diagnostic skin test?
TB skin test (PPD).
What is immunotherapy?
Treatment that modifies immune responses.
What are examples of immunotherapy?
Allergy shots, monoclonal antibodies, checkpoint inhibitors.
What is an epinephrine (EpiPen) used for?
Treating severe allergic reactions (anaphylaxis).
What are antihistamines used for?
Blocking histamine to treat allergies.
What do corticosteroids do in immune treatment?
Reduce inflammation and suppress immune responses.
What are decongestants used for?
Relieving nasal congestion from allergies or colds.
What are immunosuppressants used for?
Preventing organ rejection and treating autoimmune diseases.
What is interferon therapy used for?
Treating viral infections and cancers.
What are leukotriene antagonists used for?
Managing asthma and allergic reactions.
What are mast cell stabilizers used for?
Preventing allergic reactions.
What is a splenectomy?
Surgical removal of the spleen.
Why would a splenectomy be performed?
To manage blood disorders or immune conditions.
What are monoclonal antibodies used for?
Targeting specific diseases like cancer or autoimmune disorders.
What is recombinant DNA therapy?
A method to replace abnormal genes with normal ones.
What is T lymphocyte gene transfer?
Modifying T cells to enhance immunity.
What is a stem cell injection?
A therapy to restore immune function.
What is an autoimmune disease?
A condition where the immune system attacks the body’s own cells.
What are common autoimmune diseases?
Lupus, rheumatoid arthritis, multiple sclerosis.
What is an immunodeficiency disorder?
A condition where the immune system is weakened.
What are primary immunodeficiencies?
Genetic conditions causing immune failure.
What is an example of a primary immunodeficiency?
Severe Combined Immunodeficiency (SCID).
What are secondary immunodeficiencies?
Acquired immune deficiencies like HIV/AIDS.
What is anaphylaxis?
A severe allergic reaction requiring immediate treatment.
What is the first-line treatment for anaphylaxis?
Epinephrine injection.
What is hypersensitivity?
An exaggerated immune response to an antigen.
What are the four types of hypersensitivity reactions?
Type I (Allergic), Type II (Cytotoxic), Type III (Immune complex), Type IV (Delayed).
What is an example of a Type I hypersensitivity reaction?
Anaphylaxis or hay fever.
What is an example of a Type II hypersensitivity reaction?
Hemolytic reactions in blood transfusions.
What is an example of a Type III hypersensitivity reaction?
Lupus or rheumatoid arthritis.
What is an example of a Type IV hypersensitivity reaction?
Poison ivy or TB skin test reaction.
What is the role of histamine in allergic reactions?
It causes swelling, itching, and bronchoconstriction.
What are immunodeficiency-related infections?
Opportunistic infections like pneumonia or candidiasis.
Why do HIV patients have low CD4 counts?
HIV destroys CD4 T cells, weakening the immune system.
What are the two main types of immunity?
Innate (nonspecific) and adaptive (specific) immunity.
What is innate immunity?
The body’s first line of defense, present at birth, and not antigen-specific.
What are examples of innate immune defenses?
Skin, mucous membranes, stomach acid, and phagocytic cells.
What is adaptive immunity?
Immunity that develops after exposure to pathogens and is antigen-specific.
What are the two branches of adaptive immunity?
Humoral immunity (B cells) and cell-mediated immunity (T cells).
What cells are involved in adaptive immunity?
B cells, T cells, and antigen-presenting cells.
Which immune cells present antigens to T cells?
Macrophages and dendritic cells.
What is the role of macrophages in immunity?
Phagocytosis and antigen presentation to T cells.
What do dendritic cells do?
Capture antigens and present them to T cells to activate an immune response.
What are cytokines?
Chemical messengers that regulate immune responses.
What are examples of cytokines?
Interleukins, interferons, and tumor necrosis factors (TNF).
What do interleukins do?
Promote communication between immune cells.
What is the function of interferons?
Help the body fight viral infections.
What does TNF (tumor necrosis factor) do?
Helps with inflammation and can kill cancer cells.
What is the major histocompatibility complex (MHC)?
A set of proteins that help the immune system recognize “self” vs. “non-self.”
What is the function of MHC I molecules?
Present antigens from inside the cell to cytotoxic T cells (CD8+).
What is the function of MHC II molecules?
Present antigens from outside the cell to helper T cells (CD4+).
What type of immunity do vaccines induce?
Active artificial immunity.
Which cells help activate B cells?
Helper T cells (CD4+).
What is clonal selection?
The process where only B or T cells specific to an antigen are activated.
What are plasma cells?
B cells that produce large amounts of antibodies.
What is opsonization?
The marking of pathogens for destruction by phagocytes.
Which immune cells are responsible for immunological memory?
Memory B cells and memory T cells.
What is herd immunity?
When a large percentage of the population is immune, reducing disease spread.
What is an adjuvant in vaccines?
A substance that enhances the immune response to an antigen.
What is a toxoid vaccine?
A vaccine using inactivated bacterial toxins (e.g., tetanus, diphtheria).
What is a live attenuated vaccine?
A vaccine with a weakened form of the pathogen (e.g., measles, mumps, rubella).
What is an inactivated vaccine?
A vaccine with a killed pathogen (e.g., polio).
What is an mRNA vaccine?
A vaccine that instructs cells to make viral proteins to trigger immunity (e.g., COVID-19).
What is an example of a subunit vaccine?
Hepatitis B vaccine.
What is an example of a conjugate vaccine?
Hib (Haemophilus influenzae type b) vaccine.
What is an example of a recombinant vaccine?
HPV vaccine.
What are primary lymphoid organs?
Bone marrow and thymus.
What are secondary lymphoid organs?
Spleen, lymph nodes, tonsils, and Peyer’s patches.
What is the function of the bone marrow?
Produces blood cells, including lymphocytes.
What is the role of the thymus?
Matures T cells.
Where is the thymus located?
In the mediastinum, above the heart.
What happens to the thymus with age?
It shrinks and decreases function.
What do lymph nodes do?
Filter lymph and trap pathogens.
What is the role of the spleen in immunity?
Filters blood and destroys old red blood cells.
What are Peyer’s patches?
Lymphoid tissue in the intestines that monitors gut bacteria.
What are Toll-like receptors (TLRs)?
Proteins that recognize pathogens and trigger an immune response.
What is the primary defense against viruses?
Interferons and cytotoxic T cells.
What is the role of eosinophils?
Fighting parasites and participating in allergic reactions.
Which cells release histamine during an allergic reaction?
Mast cells and basophils.
What is the difference between Type I and Type IV hypersensitivity?
Type I is immediate (e.g., anaphylaxis); Type IV is delayed (e.g., poison ivy).
What are examples of autoimmune diseases?
Lupus, rheumatoid arthritis, multiple sclerosis.
What is an example of a Type II hypersensitivity reaction?
Hemolytic disease of the newborn (Rh incompatibility).
Which hypersensitivity reaction involves immune complexes?
Type III hypersensitivity (e.g., lupus, serum sickness).
What is graft-versus-host disease (GVHD)?
When donor immune cells attack the recipient’s tissues.
What is primary immunodeficiency?
A genetic defect causing an underdeveloped immune system.
What is an example of a primary immunodeficiency?
Severe Combined Immunodeficiency (SCID).
What is secondary immunodeficiency?
An acquired suppression of the immune system (e.g., HIV/AIDS).
Which virus causes AIDS?
Human Immunodeficiency Virus (HIV).
Which cells does HIV target?
CD4+ T cells.
What is the significance of a low CD4 count?
Increased risk of opportunistic infections.
What are common opportunistic infections in HIV/AIDS?
Pneumocystis pneumonia, tuberculosis, candidiasis.
What is the purpose of antiretroviral therapy (ART)?
To slow HIV progression and maintain immune function.
What is the “window period” in HIV testing?
The time between infection and detectable antibodies.
What is the function of neutrophils?
First responders to infections, performing phagocytosis.
What is chemotaxis?
The movement of immune cells toward infection sites.
What is the function of the complement system?
A group of proteins that help destroy pathogens.
What is a neutropenic precaution?
Measures to protect immunocompromised patients from infection.
What is the function of histamine?
Increases inflammation and vascular permeability.
What is the function of prostaglandins in immunity?
They regulate inflammation, pain, and fever.
What is immunosenescence?
The gradual decline of immune function with aging.
What is the hygiene hypothesis?
The idea that lack of early childhood exposure to microbes may lead to allergies and autoimmune diseases.
What are immune checkpoint inhibitors?
Drugs that help the immune system attack cancer cells.
What is CAR-T cell therapy?
A treatment where T cells are engineered to fight cancer.
Which vitamin is essential for immune function?
Vitamin D.
What is an acute-phase response?
A rapid inflammatory reaction involving fever and protein production.
What are examples of acute-phase proteins?
C-reactive protein (CRP) and fibrinogen.
How does fever help the immune response?
It slows pathogen growth and enhances immune activity.
