#34 Innate Immunity Flashcards
(30 cards)
Functions of the immune system
defend against invading pathogens (virus and bacteria)
Remove worn out cells and damaged tissue
identify and destroy mutant cells originating from self
can mount inappropriate response that leads to allergies or autoimmune disease
5 types of leukocytes
neutrophils, eosinophils, basophils, monocytes, lymphocytes
neutrophil function
phagocytosis
eosinophil function
parasite destruction and allergic reactions
basophils
histamine and heparin release, allergic reactions
monocytes
transform into macrophages, phagocytosis
lymphocytes (b and t)
b: secrete antibodies
T: destroy virus infected or mutant cells
innate immunity
nonspecific. nonselectively defends against foreign invaders. Rapid but limited responses
adaptive immunity
organism adapts to defend against specific invaders for long-term protection
innate immunity: how to kill
inflammation, interferon, natural killer cells, complement system
goal of inflammation
bring phagocytic cells, fluid, and proteins to the area in order to kill microorganisms, remove debris, prep for healing
5 steps of immune response
- activation of macrophages leads to phagocytosis, cytokines
- Histamine released from mast cells leads to vasodilation
- increased capilary permeability bc of histamine leads to edema, pain. clotting
- Leukocytes migrate to area (monocytes, neutrophils)
- Phagocytosis of bacteria and debris
what are mast cells?
tissue bound basophils
what is pus?
leukocytes and digested tissue
abcesses
tender, swollen, masses that are often discolored and filled with pus and bacteria
often in armpit, anus, spine, teeth, groin
How do immune cells kill bacteria?
When the body detects a foreign bacterial invader, it recruits cells known as neutrophils. These specialized cells generate reactive oxygen species – simply put, they create hydrogen peroxide. In most cases, the hydrogen peroxide will kill the invading bacteria.
Explain how and why fever happens after inflammation
When bacteria enters the body it releases exogenous pyrogens. In their attack, immune cells release endogenous pyrogens. Together, these go to the hypothalamus and stimulate prostaglandin release, which increases body temperature
How do NSAID’s work?
decrease inflammation by inhibiting production of prostaglandins and histamine ( no phagocyte secretions)
how do interferons work?
when infected by viral nucleid acid, cell produces interferon. Travels to other cells and binds, triggers production of enzymes that prevent protein synthesis and break viral RNA so virus can invade, but cannot control the cell.
Viral Lytic cycle
virus attaches, injects NA into cell. Host replicates viral DNA/RNA, causing new viruses to be assembled. Host cell eventually lyses and releases all virus particles
how do interfereons work? (Cellular mechanism)
bind to surface of cell, signal ISGF3 complex, which binds to gene promoter for anti viral proteins.
how are interfereons used in therapy?
inject the inteferon into infected area to prevent the spread of the virus
Natural Killer Cells
non-specific, will kill any virus infected or cancer cell. require no antigens, rapidly activated, but few in number
complement system
produced by liver, non-specific defense. Complements the action of antibodies. System made up of 9 proteins, normally inactive.
