Define Adaptive Defenses
respond to particular agents called antigens
Define Innate Defenses
- those that act against any type of invading agent.
- Physcial & Chemical barriers.
- Cellular Defenses.
- Molecules ener the target cell and fragment its nuclear DNA.
- (programmed cell death)
a process that allows neutrophils to congregate in tissue fluids at the injured region.
What are your physical barriers
- Mucous Membranes.
- Chemicals secreted by mucous membranes.
- Flushing out your system.
How does the mucous membranes protect you?
- Covers surfaces exposed to the outside air.
- Difficult to penetrate.
How do you Flushing out your system protect you.
How do Cilia protect you?
hairlike projections in mucous membrane that help to sweep away microbes that had entered the respiratory tract.
What antimicrobials do your cells secrete to kill invading microbes?
- Stomach acid.
What antimicrobial function does Sweat have?
High salt, low pH inhibits growth of bacteria.
What antimicrobial function does stomach acid have?
Acidic pH - major defense against intestinal pathogens.
What antimicrobial function does Lysozyme have?
Tears, saliva, mucus, cleaves peptidoglycan linkage in bacterial cell wall.
What antimicrobial function does Transferrin have?
- iron binding protein in blood.
- some bacteria require iron for enzymes.
- Limits the iron available for bacteria.
List each type of white blood cell.
- Granulocytes include:
- Agranulocytes Include:
- NK Cells.
Function of each type of Granulocytes white blood cell.
- Granuloctyes Neutrophils - Most Common phagocytes.
- Granulocytes Eosinophils - Allergies, parasitic infections.
- Granulocytes Basophils - Mast Cells, release histamine.
- Granuloctyes Dendritic - Mobile tissue phagocytes that present antigens in lymph nodes.
Functon of each type of Agranuloctyes White Blood Cell.
- Agranuloctyes Monocytes - reside in blood develop into macrophage in tissue.
- Agranulocytes Lymphocytes - B Cells make antibodies; T Cells mediated immune response.
- Agranulocytes NK - NK identify and kill virus-infected cells.
What is Phagocytosis?
digest & destroy invading microbes and foreign particles by a process.
In Phagocytosis which cells in use this defense?
What is the process of phagocytosis?
- Find invader.
- Adhere to invader.
- Ingest the invader.
- Digest the invader.
What signals does a phagocyte recognize?
- Pattern recognition receptors recognize pathogens.Peptidoglycan, Lipopolysaccarides.
- Chemical signals released by damageed cells.
- signals from other leukocytes.
How do phagocytes ingest?
- extension of the phagocyte membrane that fuse and enclose microorganism.
- forms a membrane bound vacuole with microorganism inside=phagosome.
How do phagocytes digest microbes?
- Fuse with lysosomes.
- reactive oxygen compounds are used to kill ingested microbes.
What cells do Natural Killers Cells target?
virus infected cells
How do Natural Killer cells kill cells?
NK cells trigger cell death by apoptosis=cell suicide.
What is a lymph?
extracellular fluid that circulates in through the lymphatic system
What is the function of lymph nodes?
act as a filter that catches debris from the lymph.
Which cells reside in lymph nodes?
- Other immunologically important cells.
What is inflammation?
A reaction to any traumatic event in the tissues.
What is the purpose of Inflammation?
- Mobilize and attract immune components to the site of injury.
- Set motion repair mechanisms.
- Destroy microbes and prevent further invasion.
What are Cardinal signs of Inflammation?
- Dolor:pain at infection or injured site.
What causes the signs of Inflammation?
- Increased blood flow bring clotting factors and phagocytes to the injured tissue.
- Cytokine (histamine) from damaged cells caused vasodilation.
- increased vascular permeability.
- Causes redness and heat from increased blood flow.
- leaking fludes can cause swelling.
What is pus?
An accumulation of live and dead phagocytes liquefied cell debris and bacteria.
What is a fever?
a systemic response and may accompany inflammation.
What causes a fever?
- exogenous pyrogen.
- products of infectious agents stimulates endogenous pyrogen.
- Endotoxin, viruses, bacteria.
- Endogenous pyrogen: interleukin-1 (IL-1)from macrophages, neutrophils during phagocytosis.
- IL-1 acts on the hypothalamus to reset the body's temperature.
Why is it a good thing (What's its purpose?)
- Slows growth of pathogens who prefer 36'C.
- Inactivate some microbial enzymes and toxins.
- Increases immune response by increasing chemical reaction rates.
- encourages rest.
Three type of Interfon.
- Alpha (INF-a).
- Beta (INF-b).
- Gamma (INF-y).
What is the function of Interferons?
- Both INFa & INF b function is to produce antiviral proteins in neighboring cells.
- Bind to receptors on neighboring uninfected cells.
Particularly how do INF-a & INF-b work?
- Antiviral proteins target viral RNA's.
- Some viruses produce dsRNA structure (not found in healthy cells).
- Good targets for selectively toxi agents.
- Ultimately: induce antiviral replication in the uninfected cell.
How is INF-y produced?
- Gamma Interferon is produced by lymphoid cells, lymphocytes and NK cells.
- Do NOT have to be infected by virus.
What effects of INF-y enhance innate & adaptive immunity?
- activates macrophages, NK cells, lymphocytes.
- Inhibits cancer cells.
- Stimulates B cells and other specfic immune responses.
What is complement?
- set of more than 20 large proteins that circulate in blood that play a key role in host defese.
- works as a cascade (a acts on b which acts on c...)
Whate are the three methods of destruction of Classical Complement Pathway?
- Direct Lysis.
How does Opsonization destruct?
- C3b binds to surface of antibody marked microbes.
- C3b acts as an opsonin (makes more tasty).
- Phagocytes have C3b stimulates phagocytosis.
How does Inflammation destruct?
- C3a can initiate or enhance inflammation process.
- Chemotaxis promotes diapedesis of neutrophils out of blood vessels.
How does Direct Lysis destruct?
- Complement molecules activated by C3 catalyze formation of pores in membrane.
- Pores consiste of C9 proteins.
- These pores in cell memberan or viral envelopes kill the organism.
What is a Alternative pathway?
- Polysaccharide markers on the surface of the pahtogen activate factor B which activates factor D which activates factor P.
- No antibodies involved.
What are the General Functions of the Complement System?
- 1. Enhance phagocytois by opsonization.
- 2. Lyse pathogens directly MAC Complexes.
- 3. Stimulate inflammation and immune responses
What initiates the Classic Complement Pathway?
- Antibodies bound to antigens on the surface of the microbe (bacteria).
- Complement protein C1 binds first, activates C4&C2.
- C2 activates central molecule C3.
What occurs with activation of C3?
- Three methods of destruction occur.
- Direct Lysis (MembraneAttackComplex)
What is the function of C3b?
Recognition of C3b stimulates phagocytosis