16 - Innate Immunity Flashcards
What are the characteristics of innate immunity?
fast, not specific, no memory
What are the characteristics of adaptive immunity?
slow, specific, has memory
What lines of defense are included in innate immunity?
first and second
What lines of defense are included in adaptive immunity?
3rd
What are the parts of the 1st line of defense?
- physical factors (skin, mucous membranes, body secretions-tears/saliva/earwax/urine)
- chemical factors (gastric juice, lysozymes, vaginal secretions etc.)
What are the 3 granulocytes and what do they end in?
- neutrophils
- basophils
- eosinophils
“phil”
What are the 3 agranulocytes?
- monocytes -> macrophages
- dendritic cells
- lymphocytes
Neutrophils
phagocytic - multiple lobes
Basophils
inflammation, allergies
Eosinophils
toxin against parasites, phagocytic
Monocytes
- in tissue turn to macrophages
- phagocytosis
Dendritic cells
phagocytosis (long extensions - allow for more surface area to contact with more pathogens)
Lymphocytes
NK, T, B cells (more in another chapter)
What is the main function of the lymphatic system?
to get fluid out of the tissues and filter it and then return it back to the bloodstream
What is phagocytosis?
ingestion of substance/”bad-guy”
What are the five steps of phagocytosis?
- chemotaxis (phagocyte attracted to microbe)
- ingestion (membrane expands and engulfs microbe)
- membrane surrounds microbes, inside phagosome
- digestion (phagosome and lysosome fuse to create phagolysosome
- phagolysosome with digested material is expelled from cell
What are the 3 functions of inflammation?
- destroy microbe, remove it
- confining microbe
- repair and replace damaged tissue
What are the symptoms of inflammation?
redness, pain, heat, swelling
What are the steps of inflammation?
- tissue damage (histamine, cytokines, kinins, prostaglandins released)
- vasodilation (increased blood flow - redness)
- increased permeability (migration of fluid -edema) - margination (phagocytes stick to blood vessel inner surface)
- diapedesis (phagocytes move through vessel walls)
- phagocytes destroy microbes - phagocytosis
What is a fever?
any body temperature that is higher than what it should be (100.4 and up)
What is a sign temperature is going up?
chills
What is a sign temperature is going down?
sweats
How does a fever happen?
LPS/other foreign molecule -> release of cytokines -> hypothalamus releases prostaglandins to reset thermostat -> fever
What are the 3 functions of the complement system?
- kill microbes
- aid in inflammation
- phagocytosis
What are the names of the 3 complement pathways?
- Classical pathway
- Alternative pathway
- Lectin pathway
How does the classical pathway activate C3?
- C1 is activated by binding to antigen-antibody complexes
- Activated C1 splits into C2 and C4
- C2a and C4b combine and activate C3 (which splits)
How does the alternative pathway activate C3?
- C3 combines with factors B,D, and P on the surface of a microbe
- This causes C3 to split into fragments C3a and C3b
What is the pathway after C3 (5)?
- C3 is activated through classical/alternative pathway
- C3a causes inflammation
- C3b causes opsonization and splits C5
- C5a causes inflammation and C5b activates C6, C7, C8
- C6-8 attach together and bind to the membrane and signal lots of C9 which forms a donut shaped complex which causes a hole and leads to cell death (Membrane attack complex = mac)
What is the difference between the classical and alternative pathways?
how they activate C3
What are interferons?
specific type of cytokine antiviral proteins, produced by lymphocytes and macrophages, interferes with viral replication
How do interferons work?
Basically once a cell is infected with a virus it is impossible to save it and its just better to be destroyed - so it sends a signal via interferons to its neighbor which says hey you need to arm yourself against the virus - when the neighbor gets the interferon it starts making antiviral proteins that cause the virus to degrade when it enters the cell
Which of the following is NOT part of the body’s first line of defense?
a. skin
b. mucous membranes
c. saliva
d. fever
d. fever
Which of the following is classified as an agranulocyte?
a. monocyte
b. neutrophil
c. eosinophil
d. basophil
a. monocyte
Complement proteins are numbered?
C1-C9
