Innate immunity Flashcards
What makes up the First line of defense?
- 1st line= Anatomical physical, mechanical, and chemical barriers.
What are the main physical barriers of the 1st line?
- Skin
- Cilia
- Linings of tracts
- Vomiting
Chemical barriers of the 1st line include:
- Lysozymes
- Stomach acid
- saliva
How does the normal microbiome act as protection?
Prevents the growth of pathogenic microorganisms
How can the normal microbiome be disrupted?
What occurs?
Prolonged antibiotics wipe out normal microbiome.
Opportunistic organisms (like pseudomonas/clostridium) take over
What is the 2nd line of defense of the immune system?
- Where does it occur?
Nonspecific, first immune response to vascular injury= inflammation
- Occurs in bloodstream
What are the manifestations of inflammation?
- Redness
- Heat
- Swelling
- Pain
What are the goals of inflammation?
- Prevent/limit further infection and damage
- Initiate adaptive immune response
- Initiate healing
What are the vascular responses (steps) during inflammation?
- Vessels dilate
- Increases permeability and causes fluid leakage
- Edema occurs
- WBCs enter into tissues
What is the complement system?
When is it activated?
Inactive proteins that activate when antibodies and antigens come together
What do complement protens produce when activated?
- Opsonins
- Chemotactic factors
- Anaphylatoxins
What do these substances do:
- Opsonins
- Chemotactic factors
- Opsonins= Coat pathogens making them easier to be phagocytosed by neutrophils and macrophages.
- Chemotactic factors: Attract neutrophils and macrophages
What are the three plasma protein systems?
- Complement system
- Coagulation system
- Kinin system
What does the coagulation system do?
Forms fibrinous network (made of fibrin) at injured site (clots)
What are the goals of the coagulation system?
- Prevent spread of infection
- Confine foreign bodies
- Form clots to stop bleeding
- Allow repair and healing
What does the kinin system do?
Produces bradykinin that causes dilation of blood vessels.
(this compresses nerves and causes pain)
What do these leukocytes do:
- Eosinophils
- Basophils
Eosinophils= Destroy parasites and allergies. Degrade substances released by mast cells.
Basophils= produce histamine
- causes vasoconstriction of BV and dilation of capillaries
What do these leukocytes do:
- Neutrophils
- Monocytes:
- Neutrophils: First to arrive at infections. Initial phagocytose
- Monocytes: Mature into macrophages after leaving red bone marrow.
What are the four types of cytokines?
- Chemokines
- Interleukins
- Tumor necrosis factor
- Interferons
What do these proteins do:
- Chemokines
- Inteferons
- Chemokines: Signal and attract WBCs
- Interferons: Destroy virally infected cells and warn neighboring cells
What do these types of interleukins do:
- IL-1
- IL-10
- IL-1= Endogenous pyrogen that causes fever
- IL-10= An anti-inflammatory
What does IL-6 (interleukin) do?
Causes liver to make substances that cause inflammation.
Helps with wound healing
What do mast cells do?
Release:
- Histamine
- Cytokines
- Leukotrienes
- Prostaglandins
What do these substances cause:
- Leukotrienes
- Prostaglandins
- Leukotrienes: Similar effects to histamine, but last longer
- Prostaglandins: Cause pain
