Ch:24 Immune System Flashcards
Which WBCs are classified as
Granulocytes?
Mast cells, Basophils, Eosinophils & Neutrophils
Which WBCs are classified as
Phagocytes?
Neutrophils, Macrophages & Monocytes
Which WBCs are classified as
Cytotoxic cells?
Eosinophils, Lymphocytes & Plasma cells
Which WBCs are classified as
Antigen-presenting cells?
Monocytes, Macrophages, Lymphocytes, Plasma cells & Dendritic cells
Which WBCs are the most abundant in blood?
Neutrophils
Which WBCs are the most rare?
Basophils and Mast cells
Which WBCs are involved in inflammation & allergic response?
Basophils and Mast cells
What are the differences between Innate immunity & acquired immunity?
Innate immunity recognizes pathogen-associated molecular patterns
& is mediated by phagocytes while acquired immunity recognizes specific antigens and is mediated by lymphocytes
What 2 cells are B-lymphocytes?
Plasma cells & Memory cells
What 2 cells are T-lymphocytes?
Cytotoxic T cells & Helper T cells
What are the 6 functions of Antibodies?
- Mark antigens for destruction
- Enhance inflammation
- antigen clumping
- inactivation of bacterial toxins
- Activate compliment & B lymphocytes
- Trigger degranulation
What are the 5 subclasses of antibodies?
IgG: activate complement (75% of plasma antibodies)
IgA: found in external secretions (saliva, tears, milk)
IgE: activate mast cells in allergic responses
IgM: activate compliment and involved in primary immune
response & blood group reactivity
IgD: surface of B-lymphocytes
What to subclasses of antibodies activate complements (Fc end of antibody)?
IgG & IgM
What happens in primary immune response?
exposure to an antigen triggers clonal expansion and the immune response
What happens in secondary immune response?
when memory cells are reexposed to the appropriate antigen, the clone expands more rapidly to create additional effector and memory cells
Is primary or secondary immune response faster and stronger?
secondary immune response
What is the function of T lymphocytes and where do they mature?
to carry out cell mediated immunity by binding MHC- antigen complexes on target cells and they mature in the thymus gland
What does the complement system do during a bacterial infection?
-complement proteins attract leukocytes
-cause degranulation of mast cells and basophils
-cytokines attract more immune cells
-histamine dilates blood vessels & increases permeability
-proteins & water enter extracellular fluid causing swelling
-membrane attack complex permeabilizes bacterial
membranes
What type of cells are MHC Class l and how do they function?
all nucleated cells
mark cells for destruction by cytotoxic T cells
What types of cells are MHC Class ll and what is their function?
macrophages, B lymphocytes & dendritic cells
stimulate helper T cells to secrete cytokines to enhance immune response
What are the 2 subclass cells of T lymphocytes and what are their functions?
Cytotoxic T cells- release perforin & proteases to induce
apoptosis of target cells.
Helper T cells- release interferon Y to activate
macrophages
- release interleukins to activate antibody
production & stimulate cytotoxic T
lymphocytes, mast cells & eosinophils
-release colony stimulating factors to
enhance leukocyte production
What do cytotoxic T cells bind to opposed to helper T cells?
cytotoxic T cells = MHC class l
Helper T cells = MHC class ll
What are the steps involved in immune response to a bacterial infection?
- Bacteria activates complement proteins
- Opsonins coat bacterial cells with antigens &
phagocytes engulf the uncoated bacteria - bacteria coated with antigen binds to T_H cells
- T_H cells activate B lymphocytes to become plasma cells
- Plasma cells secrete antibodies
How does the immune system respond to a bacterial infection?
- memory cells are attracted to the area & initiate 2ndary immune response
- antigen-presenting cells activate hellper T cells
- Naive B cells are stimulated to produce plasma cells & memory cells (primary immune response)
What are the steps involved in a viral infection?
- Macrophages ingest virus
- MHC ll on macrophage presents the virus antigen
- macrophage secretes cytokines to induce inflammation and attract Helper T cells to bind to macrophage
- once bound, T_H cells activate B lymphocytes to become plasma cells that secrete antibodies
- T_H cell activate cytotoxic T cells at T-receptor and release perforin & granzymes that induce apoptosis
How are viruses prevented from entering cells in the body?
Opsonins mark virus for macrophages to ingest
What do macrophages release to prevent the virus from replicating?
a-interferons
How do cytotoxic T cells recognize infected cells and what do they release to promote apoptosis
MHC class l (different than macrophages MHC ll)
release perforin and granzymes to induce apoptosis
What is it called when during the primary immune response, naive B lymphocytes divide to form plasma and memory cells?
Clonal expansion
What occurs in the primary immune response?
clonal expansion (naive B lymphocytes divide to form plasma and memory cells)
What occurs in the secondary immune response?
memory cells reproduce for a rapid response
Where do all nucleated cells display the foreign antigen?
MHC l
What cells is humoral immunity involved in and what is it mediated by?
B lymphocytes and mediated by antibody secretion
What cells is cell-mediated immunity involved in and what is it mediated by?
T lymphocytes and mediated by T cell receptors binding to MHC-antigen complexes?
What is the summary of the immune response in a bacterial infection?
activation of complement, phagocytosis of bacteria, primary & secondary response
What is the summary of the immune response regarding a viral infection?
primary and secondary immune response against free virus, ingestion of virus by macrophage, activation of cytotoxic T cells to kill infected cells
How do histamines cause inflammation?
dilating blood vessels & increasing permeability
What is the role of helper T cells?
stimulate antibody production by B cells
What 2 cells do helper T cells activate and what does the activated cell become?
B lymphocytes to become plasma cells
&
cytotoxic T cells to release perforin & granzymes
What do cytotoxic T cells secrete and what do the secretions cause?
perforin & granzymes for apoptosis
What are the 6 steps in an allergic response?
- allergen ingested & processed by antigen-presenting cell
- antigen-presenting cell activates Helper T cell
- Helper T cell activates B lymphocyte
- B lymphocyte becomes plasma & memory cells
- Memory B and T cells retain memory of exposer to allergen
- upon reexposer to allergen, B & T cells activate more quickly. The body reacts strongly by releasing histamines, cytokines, and other mediators causing allergic symptoms
What type of antigens and antibodies are present on type O blood?
Antigen: NONE
Antibody: A & B
What type of antigens and antibodies are present on type A blood?
Antigen: A
Antibody: B
What type of antigens and antibodies are present on type B blood?
Antigen: B
Antibody: A
What type of antigens and antibodies are present on type AB blood?
Antigen: A & B
Antibody: NONE
What does a massive release of histamine cause in an allergic rxn?
systemic vasodilation, bronchoconstriction, and collapse of the circulatory system
What happens during reexposer during an allergic response?
allergen binds to IgE on Mast cells releasing histamine and cytokines
What happens during sensitization during an allergic response?
- allergen is ingested by macrophage
- helper T cells are activated
- helper T cells activate B cells to become plasma cells making IgE & IgG
- IgE binds to Mast cells and basophils
How are foreign organs rejected by the body?
foreign MHC proteins activate cytotoxic T cells & helper T cells which kills foreign tissue
How are autoimmune diseases caused?
T lymphocytes recognizing self HLA are eliminated by the thymus—> failure of this system results in autoimmune disease
