Test 3 - Intro To Immune System Flashcards
What is a pathogen?
Organism that has the potential to cause disease.
What are the 4 classes of pathogens?
Bacteria
Viruses
Fungi
Parasites
What are the 5 roles of the immune system?
Kill or control pathogens
Control disease
Repair tissue damage
Organ development
Maintain organ integrity and function
What is variolation vs vaccination?
Powdered disease (smallpox) put subcutaneously on skin. Early times.
Vaccination is the most successful development in public health to date
What are 3 endogenous antimicrobial properties?
Sebum
Low pH
Commensalism organisms
Immune response when barriers are compromised. 5 steps.
Wound introduces bacteria
Resident effector cells activated and secrete cytokines
Vasodilation, increased vascular permeability
Fluid, protein, and inflammatory cells to leave blood and enter tissue
Inflammation - redness, heat, swelling, pain
What is the complement system for how the immune system destroys pathogens? (4 steps)
Bacteria surface induces cleavage and activation of complement (proteins made in the liver)
Complement fragment covalently bonds to the bacteria and attracts other effector cells
The complement receptor on the effector cell binds to complement fragment bonded to bacterium
Effector cell engulfs the bacterium, kills, and breaks it down
Along with complement, there are other effector mechanisms. Name 3 of them.
Phagocytosis
Granule release
-This destroys local healthy tissue, too.
Targeted cell death
-CD8 T-Cells
The immune system has two branches. Name and describe each of them with 4 things about each.
Innate
- Rapid response (Hours)
- Fixed response
- Limited pathogen specificity
- Consistent response
Adaptive
- Slow response (Days to weeks)
- Flexible response
- Very selective pathogen specificity (Due to memory cells)
- Response improves with exposure
The innate and adaptive immune systems work in concert. T/F - Adaptive system REQUIRES an innate response.
TRUE! Without it, the adaptive system cannot handle the pathogen.
What are some principal components of the innate immune system? (5)
Epithelial barriers Phagocytes Dendritic cells (antigen presenting) Complement NK cells
What are some principal components of the adaptive immune system? (5)
B lymphocytes Antibodies T lymphocytes Effector T cells Helper cells
Immune cells function thru direct and indirect interactions. What are the 2 direct interactions and what are the 3 indirect interactions?
Direct
- Phagocytosis
- Immune synapse: T cell-mediated killing
Indirect
- Cytokines
- Chemokines
- Cytotoxins
WBC distribution in the blood mnemonic.
Never - Neutrophil: 40-75% Let - Lymphocytes: 20-50% Monkeys - Monocytes: 2-10% Eat - Eosinophils: 1-6% Bananas - Basophils: <1%
Both the adaptive and innate system cells come from what singular progenitor?
Hematopoietic stem cell
In the adaptive system, what is the beginning cell?
Common lymphoid precursor
The common lymphoid precursor goes to 2 cells. What are they?
NK/T cell precursor
B cell
The B cell turns into what?
Plasma cell
The NK/T cell precursor turns into what two cells?
T cell
NK cell
The T cells turns into what?
Effector T cell
What is the beginning cell of the innate system?
Common myeloid precursor
The common myeloid precursor turns into what two cells?
Granulocyte-macrophage progenitor
Megakaryocyte/erythroid progenitor
The megakaryocyte/erythroid progenitor turns into what two cells?
Megakaryocyte
Erythroblast
Megakaryocytes produce what?
Platelets
Erythroblasts turn into what?
Erythrocytes
The granulocyte-macrophage progenitor turns into what 5 cells?
Macrophage and dendritic cell precursor
Neutrophil
Eosinophil
Basophil
Unknown precursor
The unknown precursor turns into what?
Mast cell
The macrophage and dendritic cell precursor turns into what two cells?
Monocyte
Dendritic cell
The monocyte turns into what?
Macrophage
*Also can be turned into a dendritic cell, although pathway is unknown
Look in photos for the chart of the cells.
Do it. Be able to draw it.
Neutrophils are part of what system and what do they do?
Innate
Engulf and kill microorganisms
**The neutrophil then dies after completing its function. ITS KAMAKAZI
Monocytes are part of what system, what do they turn into, and what do they do?
Innate
Dendritic cells
Macrophages
Basically a neutrophil, but with more specialized functions.
-Express degraded antigen to the adaptive system
—Dendrites vacuum up antigens, travel to lymph, and are main drivers of immunity
—Macrophages also clear the damaged tissue after their function
**These cells do NOT die after their functions
Macrophages kill by what and promote what?
Phagocytosis
Inflammation
What cells are in the adaptive system?
T cells
- Mature in thymus
- Helper T cells and Cytotoxic T cells
B cells
- Mature in bone marrow
- Memory cells
Natural Killer (NK) cells
What provides specificity in the adaptive immune system?
Clonal expansion
*When an antigen binds a lymphoid cell, then that cell rapidly replicates and eradicates the antigens
Adaptive immunity responses are humoral and cellular. What are the differences?
Humoral - Antibody mediated (blood)(B-cells)
Cellular - Cell-cell interaction mediated (T-cells)
What are the 5 types of antibodies that mediate humoral responses and something about them?
*MADGE
IgM - First antibody produced and released
IgA - Secreted from mucosal glands
IgD - B cell surface antibody
IgG - Most abundant antibody
IgE - Basophil and mast cell surface antibody
T cells resolve pathogens thru what two things?
Direct killing
Immune support
What are the two classes of T cells?
Cytotoxic (CD8) T Cells
Helper (CD4) T Cells
What do CD8 (cytotoxic) T Cells do?
Kill altered self cells
-Cancer, virus, bacteria
What do CD4 (helper) T cells do?
Support other immune functions
- Many subtypes
- Regulatory function
- Communicate with, improve, and activate B cells
What are primary lymphoid organs?
Where immune cells develop
- Bone marrow
- Thymus
What are secondary lymphoid organs?
Where adaptive responses initiate
- Lymphoid system
- Spleen
- Mucosa-Associated Lymphoid Tissue (MALT)
What is the response to infection in the immediate innate response?
0-4 hrs
Pathogen invades
Pathogen recognized by effector molecules
Pathogen eliminated and very minor tissue damage is repaired
-If not, the induced innate immune response occurs
What happens in the induced innate immune response?
4 hrs to 4 days
Activation of resident cells in the tissue and recruitment of effector cells to the tissue. INFLAMMATION, FEVER, ACUTE PHASE RESPONSE
Effector cells recognize and attack the pathogen
Pathogen eliminated and minor tissue damage is soon repaired
-If not eliminated, adaptive immune response activated
What happens in the adaptive immune response?
4 days until defeat of pathogen, defeat of host, or truce of chronic disease.
Secondary lymphoid tissue close to infected tissue is alerted
B and T cells proliferate and become effectors and travel to site
Pathogen eliminated and major tissue damage is gradually repaired
-If not, host dies, or suffers disease from chronic infection
What is the basic 9 step process of pathogen resolution?
1-Injury/pathogen infiltration 2-Resident immune cells respond 3-Inflammatory response 4-Innate pathogen targeting 5-Pathogenic antigens presented in the lymph nodes 6-Adaptive immunity initiated 7-Ongoing immune response 8-Pathogen destroyed or sequestered 9-Memory cells formed
