Bio 112 Ch. 43: The Immune System Flashcards
_______, agents that cause disease, infect a wide range of animals, including humans.
Pathogens.
The _________ recognizes foreign bodies and responds with production of immune cells and proteins.
Immune System.
All animals have __________, a defense active immediately upon infection.
Innate Immunity.
Vertebrates also have _____________; refers to antigen-specific immune response.
Adaptive Immunity.
In __________, recognition and response rely on traits common to groups of pathogens.
Innate Immunity.
- found in all plants/animals
- in vertebrates, 1st response to infections and serves as foundation to adaptive immunity.
In insects, an _________ made of chitin forms 1st barrier of pathogens.
Exoskeleton.
The digestive system is protected by a chitin-based barrier and _______, an enzyme that breaks down cell walls.
Lysozyme.
Hemocytes circulate within hemolymph and carry out ________, the ingestion and digestion of foreign substances including bacteria; hemocytes also secrete antimicrobal peptides that disrupt the plasma membranes of fungi and bacteria.
Phagocytosis.
Innate defenses include (3):
- Barrier Defenses
- Phagocytosis
- Antimicrobal Peptides
Additional defenses unique to vertebrates include (3):
- Natural Killer Cells
- Interferons
- Inflammatory Response
Barrier Defenses:
- Barrier defenses include the skin and mucous membranes of the respiratory, urinary, and reproductive tracts
- Mucus traps and allows for the removal of microbes
- Many body fluids including saliva, mucus, and tears are hostile to many microbes
- The low pH of skin and the digestive system prevents growth of many bacteria
Cellular Innate Defenses; Pathogens entering the mammalian body are subject to phagocytosis; Phagocytic cells recognize groups of pathogens by: __________
TLRs, Toll-like receptors
A white blood cell engulfs a microbe, then fuses with a lysosome to destroy the microbe; there are 4 different types of phagocytic cells:
*MEND*
–(1) Neutrophils engulf and destroy pathogens
–(2) Macrophages are found throughout the body. “large eaters”
–(3) Dendritic cells stimulate development of adaptive immunity
–(4) Eosinophils discharge destructive enzymes
___________circulate through the body and detect abnormal cells and release chemicals leading to cell death, inhibiting the spread of virally infected or cancerous cells
Natural Killer Cells.
___________ proteins provide innate defense, interfering with viruses and helping activate macrophages; about 30 proteins make up the _____________, which causes lysis of invading cells and helps trigger inflammation
Interferons; complement system.