Biology - Chapter 11.3: Human Immune System Flashcards
Innate Immune System
- First line of defense
- Nonspecific immune response (generalized)
Outer Walls
1) Skin
2) Cilia
3) Stomach acid
4) Symbiotic bacteria
Rally signaling
Mast cell release histamine which dilates blood vessels, making vessels more permeable to let immune cells into tissue
DAT Mnemonic for 5 Signs of Inflammation
S welling L oss of function I ncreased heat P ain R edness
Diapedesis
Process by which cells move from capillaries to tissues in order to fight pathogens.
DAT Mnemonic Five Main Types of Leukocytes from Highest to Lowest Quantity
N ever (Neutrophils) L et (Lymphocytes) M onkeys (Macrophages/Monocytes) E at (Eosinophils) B ananas (Basophils)
Neutrophils
- Phagocyte
- Innate immunity
- Make up over half of all leukocytes
Lymphocytes
- B and T Cells (Adaptive Immunity)
- Natural Killer Cells (Innate Immunity)
NK Cells
- Natural Killer Cells
- Attack virally-infected cells + cancerous cells
- Use perforin to create holes and granzyme to lyse cells
Macrophages/Monocytes
- Phagocyte
- Innate immunity
- Can act as antigen-presenting cells to activate adaptive immunity
Eosinophils
- Have granules that kill pathogens, parasites
- Innate immunity
Basophils
-Similar to mast cells
Dendritic Cells
- Part of innate immunity
- Scan tissues using pinocytosis/phagocytosis
- Migrate to lymph nodes to activate adaptive immunity
Interferons
- prepare cells for virus attack
- activate dendritic cells
Complement System
- Group of approximately 30 proteins that aid immune cells in fighting pathogens
- Turn on each other via complement cascade
- Release cytokines
Complement Protein Actions
- Opsonization (tags antigens for phagocytosis)
- Amplifies inflammatory response
- Forms membrane attack complex
Adaptive Immune Response
-specific immune response (targets specific antigens)
MHC
- Major Histocompatibility Complex
- recognizes self proteins from non-self proteins
MHC Class I
-Present on all nucleated cells
MHC Class II
- Surface molecule present on antigen-present cells
- Used to present foreign antigens to activate immune cells
B Cells
- Control antibody-mediated immunity
- manage production and release of antibodies
- activate antigen-presenting cells
Antibodies
- Immunoglobins
- Structurally identical to b cell receptors but freely circulate in blood and lymph
- Tag antigens for phagocytosis, neutralize the antigen by coating it, or activate the complement system
DAT Mnemonic Classes of Antibodies
Me (IgM) And (IgA) Eve (IgE) Don't (IgD) Go (IgG)
IgM
- largest antibody
- first antibody to be produced and activates the complement system
IgA
- in bodily secretions (binds externally)
- passive immunity via breast milk
IgE
- antigen receptor in basophils and mast cells
- triggers allergic reaction when bound to an allergen releases histamine
IgD
-only small amounts are produced
IgG
- Most abundant antibody in circulation
- Only antibody that can cross the placenta and give fetus passive antibody
Memory B Cells
- Survive for a long time and lay dormant until reactivated by the same antigen
- Trigger original clonal expansion
- After reactivation, memory B cells cause massive antibody production
T-Cells
- control cell mediated immunity by directly actin on cells instead of sending antibodies out
- unique T cell receptors
- Must bind to antigens presented on antigen-presenting cells to be activated
MHC I Presentation
- T Cells differentiate into CD8 T Cells (Cytotoxic T Cells)
- Kill infected cells through perforin and granzymes
- More specific and require antigen presentation, unlike natural killer cells
MHC II Presentation
- T Cells differentiate into CD4 T Cells (helper T Cells)
- Helper T Cells release cytokines to boost both innate immunity and adaptive immunity
- Help attract other cells and increase proliferation of other T and B Cells
Passive Immunity
- Receiving antibodies from another organism that already has that immunity
- placenta, breast feeding
Active Immunity
-Already had been infected once already by pathogen and contains memory B and T Cells
