Chapter 43 (Module 4) Flashcards
Innate Immunity: (5)
- a few different general receptors (viruses, bacterium, and fungi)
- all animals have innate immunity
- it is present when you are born
- develops more rapidly
- includes barrier defenses (skin, shells, exoskeletons, etc.)
Adaptive Immunity: (4)
- many receptors for specific parts of the proteins on viruses
- only vertebrates have adaptive and innate
- it develops after the innate response
- adaptive is slower
Barrier defenses in Insects (Invertebrates): (3)
Barrier/Physical
- exoskeleton
- chitin in digestive tract
Barrier/Chemical
- Lysozyme breaks down bacterial cell walls in digestive system
Cellular defenses in Insects (Invertebrates): (2)
if pathogens get through the 1st layer, the immune system produces proteins that recognize the pathogens
Phagocytosis:
when an immune cell
Phagocytic cell in insects:
Hemocytes
Innate immunity defense against RNA viruses: (2)
- Host cells convert the single strand of RNS to a double strand
- There are not double stranded RNA segments in animals so it triggers self-defense
Cellular innate immunity in Vertebrates: (4)
MAIN WBC
*Neutrophils
*Macrophages
OTHER
- Dendritic cells
- Eosinophils
*Neutrophils:
phagocytic and circulating in blood all the time.
*Macrophages:
either residing in organs and tissues or migrating through the blood.
Dendrit cells:
stimulate development of adaptive immunity
Eosinophils:
discharge destructive enzymes against parasites
Phagocytic cells: (4)
*Main WBC
1. Neutrophils
2. Macrophages
Others
3. Dendrite cells
4. Eosinophils
Natural killer cells: (3)
- Non-phagocytic
- circulate throughout the body and detect viruses, infected cells, and cancerous cells
Mast cells: (4)
- Non-phagocytic
- Between skin and muscles
- Inflammatory response if pathogens break through a barrier
How do pathogens get into the lymphatic system? (2)
- Pathogens enter lymph through interstitial fluid (excess fluid and pus from inflammation or infection)
- Lymphatic vessels then carry lymph to lymph nodes and lymphoid organs
Streptococcus pneumoniae in the immune system:
- Causes pneumonia and meningitis in humans.
- Avoids destruction because the outer capsule interferes with molecular recognition and phagocytosis.
Mycobacterium tuberculosis in the immune system:
- Causes tuberculosis (TB) (kills 1 million people per year)
- Can be recognized and engulfed by host cell but resists breakdown and grows and reproduces within the host cell
2 types of lymphocytes in adaptive immunity:
- T cells: made in the thymus (lymphatic and endocrine system)
- B cells: made in bone marrow
Antigens:
- substances that can elicit a response from a B or T cell, foreign, large molecules, proteins, or toxins secreted by pathogen
Antigen Receptors:
- proteins on the B or T cells that bind to a specific part of one molecule of a pathogen. (millions of different antigen receptors)
Epitope:
the part of the antigen that binds to the antigen receptor.
B cells: (3)
- Binding of a B cell antigen receptor to an antigen activates cells that
- … produce more antigen receptors and secrete them (called antibodies)
T cells:
- T cells bind only to antigen fragments displayed by host cell
- a T cell can then bind to the antigen fragment and the MHC molecule.
