Ch,36 immune system continued Flashcards
What are the innate defenses?
barrier defenses, phagocytosis, and antimicrobial peptides
What are the defenses unique to vertebrates?
natural killer cells, interferons, and the inflammatory response
Barrier defense
-a form of innate defense that includes
-SKIN and MUCOUS secretions,
-membranes that line the digestive, respiratory, urinary, and reproductive tracts
What does mucous do?
Traps pathogens and other particles
Positive result of body secretions
secretions such as saliva, mucous, and tears are hostile to pathogens
How does low pH help the digestive system?
Prevents growth of many bacteria
Toll-like receptors
when phagocytic cells recognize groups of pathogens
Two main types of phagocytic cells and their functions
- Neutrophils- These circulate the blood and are attracted by signals from infected tissues
- Macrophages- Larger phagocytic cells
Two additional innate defense cells and their function
- Dendritic cells- stimulate adaptive immunity in cells that contact the environment
- Eosinophils(E=E) - destructive enzymes
Interferons
- Provide innate defense. Interferes with viruses and helps activate macrophages
The complement system
Consists of about 30 proteins activated by substances on the surface of pathogens. Activation can lead to lysis of invading cells
Inflammatory response-
such as pain or swelling is brought about by molecules released upon injury or infection
Activated macrophages release Cytokines
signaling molecules that recruit neutrophils to the site of injury or infection
Mast cells release histamines
Triggers blood vessel to dilate and become more permeable
activated complement proteins
= more histamine release
