Chapter 8 - Immune System Flashcards
What is the spleen?
Location of blood storage and activation of B-cells
What are lymph nodes?
Filter lymph and site where immune responses can be mounted
Tell me the story of macrophages
When a pathogen breaks the first barrier of the immune system
1) macrophage engulfs the pathogen
2) digests the invader using enzymes
3) it presents pieces of the invader to other cells using Major histocompatibility complex
(MCH)
4) they release cytokines to stimulate inflammation
What are some examples of macrophages in different parts of the body?
Microglia in the CNS
Langerhans cells in the skin
Osteoclasts in bone
What are the two main classes of MHC?
MHC class 1:
- in all uncleared cells in the body
- the endogenous pathway
- it binds antigens from inside the cell
- cells can then be killed by T-cells
MHC class 2:
- exogenous antigens
- coming from outside the cell
What are examples of MHC class II , professional antigen-presenting cells ?
- Macrophages,
- dendritic cells in the skin
- B-cells
- certain activated epithelial cells
Natural killer cells
They can detect if MHC has been downregulated (by a virus)
**they induce apoptosis in these virally infected cells
**can also offer protection from growth of cancer
Natural killer cells: don’t mess, they will basically plant a bomb in you so you explode (apoptosis)
What are three common types of Granulocytes
Basophils
Neutrophils
Eosinophils
What is the most popular leukocyte in blood?
Neutrophils
Tell me about neutrophils
Short lived
- phagocytic
- target bacteria
- they follow them using chemotaxis!!!
- sensing different products from bacteria
- can detect bacteria once opsonized
- marked w antibody from a B-cell
Fun fact: Pus is from dead neutrophils
What are eosinophils ?
Involved in allergic reactions and invasive parasitic infections
Then they RELEASE HISTAMINE!
- causes vasodilation and leakiness in blood vessels
- allowing addditional immune cells to move out of bloodstream
Basophils
Involved in allergic responses
*closely related to mast cells
**release lots of HISTAMINE…leading to inflammatory responses
What is the adaptive immune system ?
Can identify specific invaders and mount an attack against that pathogen
What are the two divisions of adaptive immune system?
HUMORAL IMMUNITY
- Bcells
CELL-MEDIATED (CYTOTOXIC) IMMUNITY
- T-cells
What is humoral immunity?
Type of adaptive immunity
Involves production of antibodies from B-cells
What are the three fates of antibodies secreted into body fluids?
1) once bound to specific antigen, antibodies attract other leukocytes to phagocytize them
OPSONIZATION
2) may cause pathogens to clump together
- AGGLUTINATE
- then they get phagocytized
3) they can block ability of a pathogen to invade tissues (by neutralizing it)
What are the two types of daughter cells produced by by B-cells
Memory B cells:
- hang out in lymph nodes waiting for another invasion
Plasma Cells:
- produce large amount of antibodies
- **this is the basis for vaccination
What is cytotoxic immunity (in a nutshell)?
Type of adaptive immunity based on cell0mediated immunity ..
ACTIVATION of T-CELLS
What is positive and negative selection of T-cells?
Positive: maturing only cells that can respond to presentation of antigen on MHC
Negative: causing apoptosis in cells that are self-reactive
What is OPSONIZATION?
Once bound to an antigen, antibodies can attract other leukocytes to phagocytize the antigens
What is agglutination
Clumping up antibodies before they get phagotycised
What are mast cells for?
They cause inflammatory response to pathogens
What is the purpose of the constant region of antibodies
Binds to immune cells and tells them to get to work
What is a naive B-cell?
Have not been exposed to antigen
- slow response
What are the three major types of T-cells?
1) helper T-cells
2) Cytotoxic T-cells
3) suppressor t-cells
What are helper T-cells?
Also called CD4+ T cells
- coordinate immune response by secreting lymphokines
- other immune cells are recruited
What are cytotoxic T-cells ?
CD8+ cells
*capapble of directly killing virally infected cells by injectent toxic chemicals that promote apoptosis into the infected cell
CD8+ respond to MHC1 molecules so more effective against VIRAL infections
What are suppressor or regulatory T-cells?
Treg
Also express CD4 but can also express protein Foxp3
These cells help to tone down immune response
Help prevent autoimmune diseases by turning off self-relative lymphocytes
Learn the lymphatic system
Its only a few pages in the back if you have time
