Chapter 17-Innate immunity Flashcards
Why is immunology important?
pathogens enter our bodies everyday, micro biome, opportunistic infections
First line of defense
-innate non specific
-present at birth
-includes external barriers
Second line of defense
-Adaptive specific
-Develops as the body is exposed to antigens throughout life
Innate immunity
non specific
always prepared and ready
does not remember infectious agents
act immediately after exposure
anatomic, physiological, phagocytic, inflammatory
Adaptive immunity
Highly specific
Only comes for antigenic challenge
remembers infectious agents
require time before it can act on foreign substances
humoral and cell medicated components
Physical barriers
skin, mucous membranes, BBB
Mechanical defenses
Peristalsis of intestines, mucociliary escalator of respiratory tract remove microbes, shedding of skin cells, flays hint of urine
Lysozyme (First line)
degrades peptidoglycan
Lactoferrin/transferrin (first line)
bind iron, starves microbes of iron required for growth
AMPS (first line)
defensins form pores in microbial membranes
Neutrophils
phagocytic, engulf and destroy bacteria, granules contain enzymes, increase during infection
Basophils
involved in allergic reactions and inflammation, release, histamine, and heparin
Mast cells
similar to Basophils, but confined to tissues
Eiosinophils
fight, parasitic worms, involved in allergic reactions, contain histamine 
PAMP’s
pathogen associated molecular patterns,
structures are molecules common to many groups of pathogens, example: peptidoglycan, flagellin, lipopolysaccharide, Lipo peptides, nucleic acid
Cytokines
Chemical messengers, regulate leukocyte response, host physiology
PRR (pattern recognition receptors)
see signs of microbial invasion, lead to cytokine secretion (located on cell surface, an Endosome, and phagosome, free in cytoplasm)
Toll like receptors
host Cell receptors that recognize unique bacterial components.
Toll like receptors
anchored in membranes of sentinel cells, monitor, extracellular environment
Cytokines
soluble proteins, chemical messengers, produce in response to an antigen, regulate the innate and adaptive, immune system’s, formation of blood cells
Chemokines
recruit WBC to site of infection, tissue damage, inflammation
CSF
multiplication and differentiation of leukocytes
Interferons
Control of viral infections, regulation of immune responses
interleukins
produced by leukocytes, important, and innate and adaptive immunity
Tumor necrosis factor
inflammation, apoptosis
Interferons
stimulate nearby cells to stop transcription, shut down proteins synthesis, which inhibits, viral replication, promote apoptosis in cells, infected with virus
complement system 
compliments activities of adaptive immune system
three ways the complement system is activated? 
-alternative pathway – C3 binds to foreign invaders and recruits other proteins in the cascade
-lectin pathway
-classical pathway
alternative pathway
triggered when C3 B binds to foreign cell surfaces
lectin pathway
triggered by the binding of mannose binding lectin‘s to mannose on microbial cells
classical pathway
activated by antibodies, bound to antigen, which interact with complement system
