chapter 21 part A Flashcards
____ provides resistance to disease
immune system
immune system is made up of two systems
________
- 1st line; mucous membrane, skin
-2nd line; antimicrobial proteins, phagocytes, inflammation
_______
-3rd line; attack particular foreign invaders
innate (nonspecific)
adaptive (specific)
phagocytes, NKC, inflammatory response (macrophages, mast cells, WBC, inflammatory chemicals), antimicrobial proteins ( interferons and complements) pattern recognition receptors are all part of the what line of defense?
2nd
WBC that ingest and digest foreign invaders
phagocytes
most abundant phagocyte, but die fighting; become phagocytic on exposure to infectious material
neutrophils
develop from monocytes and are chief phagocytic cells; most robust phagoctye
macrophages
wander thru tissue spaces; ex: aveolar macrophages
free macrophages
permanent residents of some organs like microglia in the brain
fixed macrophages
- phagocyte adhere to pathogen or debris
- phagocyte forms pseudopods that eventually engulf the particle forming a phagosome
- lysosome fuse with phagocytic vessel, form phagolysosome
- toxic compounds and lysosomal enzyme destroy pathogens
- sometimes exocytosis of the vesicale remove indigestible/residual material
phagocytosis
opsonization
immune system uses antibodies or complement proteins as opsonins that coat pathogens (coat a microorganisms and provide binding sites)
opsonins
act as handle for phagocytes to grab on to, enhancing phagocytosis
cytoplasmic extensions
pseudopods
phagocytic vesicale
phagosome
phagosome fsing with lysosome
phagolysosome
kill pathogen resistant to lysosomal enzyme by
- releasing cell killing free radicals
- produce oxidizing chemicals
- increase pH and osmolarity of phagolysosome
respiratory burst
microbe killing proteins in neutrophils
defensins
- nonphagocytic that patrol blood and lymph
- can kill cancer and virus infected cells b4 activating adaptive immune system
- attack cells that lack “self” cell surface receptors
- kill by apoptosis
- secrete inflammation enhancement chemicals
Natural killer cells
triggered when body tissues are injured
- redness, heat, swelling, pain
- prevent spread of damaging agents
- dispose of cell debris and pathogen
-alert adaptive system
inflammation
when chemicals are released into ECF by injured tissues, immune cells, or blood proteins
ex: histamine is released by mast cells is key inflammatory chemicals
inflammatory chemical release
macrophages and epithelial cells of boundary tissues bear special pattern recognition receptors called
toll like receptors TLRs
activated TLRs trigger release of _____ that promote inflammation
cytokines
cell signaling molecules that stimulate movement of cells toward site of inflammation, infection
cytokines
-cause vasodilation of local arterioles
-make capillaries leaky
-attract leukocytes to area
-
kinins, prostaglandins, complement
vasodilation causes_____ that leads to redness and heat
hyperemia
congestion with blood
hyperemia
fluid containing clotting factors and antibodies
exudate
release of neutrophils from bone marrow in response to leukocytosis- inducing factors from injured cells
leukocytosis
endothelial cells of capillaries in inflamed area project cell adhesion molecules into vessel lumen that grab onto passing neutrophils, causing them to slow, clinging to wall
margination
neutrophils flatten and squeeze between endothelial cells, moving into interstitial space
diapedesis
inflammatory chemicals act as chemotaxis agents that promote positive chemotaxis of neutrophils toward injured area
chemotaxis
creamy yellow mixture of dead neutrophils, tissue, pathogens
Pus
collagen fibers are laid down, walling off sac of pus
abscess
bacteria resistant to digestion by macrophages can form a tumor like growth
area of infected macrophages surrounded by uninfected macrophages and outer capsule
granulomas
enhance innate defense by
- attacking microorgansims directly
- hindering mircoorgansms reproduction ability
- interferons and complement proteins
antimicrobial proteins
family of immune modulating proteins
enter neighbring cells to stmulate production of protein that block viral reproduction
-alpha/beta actiate NK cells
interferons (IFN)
- secreted by lymphocytes
- activate macros
- widespread immune mobilizing effects
- used to treat Hep C, genital warts, MS
interferons gamma
-consist of 20 blood proteins that circulate blood in inactive form
-proteins c1-c9, B,D,P, regulatory proteins
-major mechanism for destroying foreign substances
-activation enhances inflammation
-directly destroy bacteria
enhance both systems
complement system
- antibodies 1st bind to invading organism then to complement component, activating them
- double binding- complement fixation
- initial complement protein activated, cascade occurs
classical pathway for complement system
double binding
complement fixation
- lectins produced by innate system to recognize foreign invaders
- lectin binds to specific sugar on foreign invader, can also bind and activate complement
lectin pathway for complement system
- complement cascade is activated spontaneously hen certain complement factors bind directly to foreign invader
alternative pathway for complement system
this begins _____ ______
- C3b bind to target cell, trigger insertion of complement protein called membrane attack complex (MAC) into cell membrane
- MAC forms and stabilize hole in microbe membrane, influx of water
cell lysis
- abnormally high body temp
- leukos and macros exposed to foreign substances secrete pyrogens
- increase metabolic rate (increase repair rate)
fever
ac on bodys thermostat in hypothalamus, raising body temp
regulate fever
pyrogens
