Innate Immunity Flashcards
immune system
ntegrated system of organs, tissues, cells, and cell products
The first line of defense
any innate barrier that blocks invasion at the portal of entry – nonspecific (physical, chemical, microbial)
Physical Barriers to Infection
Skin and Mucous membranes
gut-associated lymphoid tissue (GALT).
Includes tonsils and Peyer’s patches
Chemical barriers to infection:
Lysozyme, pH, Digestive enzymes, antimicrobial peptides
Lysozyme
enzyme that hydrolyzes the cell wall of bacteria
pH
Lactic acid in sweat, Skin’s acidic pH, Acid in stomach
Digestion
Bacteria in our gut microbiome use
enzymes that can help break down
our ingested food more completely
than our bodies can on their own
Second line of defense
Innate immune response (protective cells and proteins,
inflammation and phagocytosis, nonspecific, present at birth)(
What is blood composed of?
RBC, WBC, and Platelets
Granulocytes:
lobed nucleus, contain granules filled with toxins that destroy pathogens
Agranulocytes:
round nucleus, kill pathogens in various ways
Neutrophils
kill ingested bacteria with toxic granules
a type of phagocyte
majority
Eosinophils
associated largely with responses to helminths (eukaryotic worms)
Basophils
some responses to parasites
smallest percentage
Monocytes
trap and phagocytose pathogens, and
participate in other immune responses
Macrophages:
critical phagocytes
Dendritic cells:
trap and phagocytose pathogens, and participate in other immune responses
PAMP:
Pathogen-Associated
Molecular Pattern
PRR:
Pathogen Recognition Receptor
Phagocytosis
Engulfing and destroying debris and pathogens.
Dendritic cells
engulf pathogens and alert lymphocytes
Chemotaxis
phagocytes detect molecules released by a pathogen, migrate
toward it, and recognize PAMPs
Ingestion
phagocyte takes up pathogen into a vesicle called phagosome
Phagolysosome
lysosome fuses with phagosome
Destruction and elimination
Degradative enzymes in lysosome break down and kill pathogen
