Lecture 11; immune system pt. 2 Flashcards
What are the jobs of Basophil?
- Target parasites and blood cancer
- Release histamine to cause inflammation
What is special about mast cells?
Reside near skin/mucus membranes
What are the three types of agranulocytes?
- Monocytes
- Dendritic cells
- Lymphocytes
What do monocytes do/become?
Mature into macrophages
Activate the 3rd line of defense
Where can you find dendritic cells?
What do they do?
Patrol portal of entry for invaders.
Help keep immune system in check
What is the job of Lymphocytes?
Natural killer: B cells/T cells
Attack microbes and tumors
B cells and T cells are part of which line of defense?
Third line of defense
An increase in these leukocytes indicates:
- Basophil
- Monocyte
- Basophil= blood cancer
- Monocyte=Inflammation
An increase in Lymphocytes indicates what type of infection?
Viral infections (if B/T cells)
What are defense molecules and what do they do?
Molecules released by leukocytes that;
- Recruit more immune cells at site of infection
- Inhibit microbe growth
- Cause fever and inflammation
What are the three types of defense molecules?
- Cytokines
- Iron-binding proteins
- Complement Proteins
What are the different classes of cytokine molecules?
- Chemokines
- Interleukins
- Interferons
- Tumor Necrosis Factor
What do chemokines do?
Induce WBC chemotaxis to recruit immune cells
What do interleukins do?
Activate immune cells
Generate fever
Stimulate hematopoiesis
What are interferons?
What do they do?
Signal given off by virally infected cells;
- Warn neighboring cells
- Kill host cell
- Signals for help
What do tumor necrosis factor do?
Stimulate inflammation and kill tumor cells
What are iron binding proteins?
What are two examples?
Proteins produced in host to sequester iron.
- Lactoferrin
- Transferrin
What do pathogenic bacteria produce to counter iron binding proteins?
What is another method for bacteria to gain iron?
Siderophores
- Break down RBC with hemolysis to get iron
What are the complement proteins?
What three things activate them?
Inactive proteins made by liver that circulate in blood.
Activated by:
- macrophages
- Neutrophils
- Blood clotting proteins
What are the three different pathways of complement proteins?
- What are they triggered by?
- Classical
- Antibodies attached to microbe
- Alternative
- Microbe itself
- Lectin
- Blood protein
What is the outcome of all three pathways (of complement proteins)?
- Opsonization (tags microbe)
- Forms the MAC (drills hole into microbe)
- Causes inflammation
What causes inflammation and what does it do?
Happens when tissue damaged from trauma/infection
- Recruit immune cells to site
- Limit spread of infection
- Deliver oxygen, nutrients, chemicals for recovery
What are the signs of inflammation?
- Redness
- Pain
- Local heat
- Swelling
What are the stages of inflammation?
- Vascular changes
- Leukocyte recruitment
- Resolution
What happens during vascular changes of inflammation?
- Vasodilation/permeability
- Fluid accumulates in tissue
- Histamine released by host cell
- Stimulate pain receptors
(Pain, swelling, and heat)
What happens during the leukocyte recruitment stage of inflammation?
- Host cell releases chemoattractants for leukocytes
- Leukocytes slow doewn in blood vessels and squeeze thru opening to site
What happens during the resolution stage of inflammation?
- Blood vessel returns to normal
- Lymphatic system removes exudate
- Pus forms (dead cells/tissue)
Why does fever occur?
Pyrogen causes release of cytokines, etc…
- molecule released by microbes
Hypothalamus increases body temp
What is considered:
- Low grade fever
- High grade fever
- Fatal fever
- Low grade= 99.5-101
- High grade= >101
- Fatal= 109.4
