Ch 14 Nonspecific Defenses Flashcards
Describe the 1st line of host defense
Nonspecific; includes any barrier that blocks invasion at the portal of entry
Describe the 2nd line of host defense
Nonspecific cellular and chemical immunity; internalized system of protective cells and fluids that include the inflammatory response and phagocytosis
Describe the 3rd line of host defense
Specific; immune response; highly specific immunity acquired on an individual basis
3rd line of defense is only found in what type of organism
only vertebrates
3 general types of nonspecific barriers
genetic, physical, & chemical barriers
4 examples of physical barriers
unbroken skin, mucous membranes, cilliary escalator, nasal hairs
6 examples of chemical barriers (chemical arsenal)
lysozyme, salt, acids, bile, oil, “other antimicrobial chemicals”
How does lysozyme work?
hydrolyzes the beta 1-4 glycosidic bond between NAG and NAM
What types of cells will salt have the least effect on?
halophiles, large cocci, gram +
immunology is the study of _____
the study of all features of the body’s 2nd and 3rd line of defense
What 2 things function as cell surface receptors
glycolipids and glycoproteins; self vs nonself
RES (reticuloendothelial system)
a support network of connective tissue fibers (reticulum) that interconnect nearby cells and meshes with the massive connective tissue network of all organs.
RES provides a niche for _____
phagocytic WBC
ECF
extracellular fluid; contained in the spaces that surround tissues
lymphatic system
compartmentalized network of vessels, cell and specialized accessory organs
lymph
a plasma like liquid carried by lymphatic circulation
lymph nodes
glands, small encapsulated bean shaped organs; filter lymph, lymphocyte storage sites
spleen
filter blood, NOT LYMPH lymphocyte storage site
thymus
site of T cell maturation
GALT
gut associated lymphoid tissue
MALT
mucosa associated lymphoid tissue
circulatory system components
heart, vessels, etc (not lungs)
Whole blood
liquid consists of blood cells suspended in plasma
serum
clear fluid from clotted blood
hematopoiesis
production of blood cells; begins in the yolk
sac–>liver–>red bone marrow (in spongy bone)
stem cells
undifferentiated cells; can become almost any cell in the body
What does an RBC do
carry O2 and CO2
platelets
involved in clotting and inflammation
myeloblast forms what 2 major types of cells
mast cells and granulocytes
what are the granulocytes
neutrophil, basophil, eosinophil
monoblast forms what type of cell
monocyte
monocyte forms what 2 cells
macrophage and dendritic cell
what is a myeloblast
WBC or leukocyte forming cell
Why are they called granulocytes
have granules that stain a characteristic way
what are granules
a mixture of toxic substances that release phagocytosis
what is the most important granulocyte
neutrophils
describe the neutrophil
most common; 50-90% of circulating WBC; produce toxic chemicals, do phagocytosis in early stages
describe basophil
scarcest; similar to mast cells but motile; function in inflammatory events and allergies
describe eosinophils
accumulate early at sites of infection and attract other WBC to release chemical mediators
eosinophils are active in large _____
eukaryotic infections like worm and fungal infections, allergy and inflammatory reactions
what are mast cells
non motile; 1st line defenders against local invasion of pathogens, recruit other inflammatory cells by releasing chemicals that cause + chemotaxis, trigger local inflammatory reactions, responsible for allergic symptoms, release of histamine, etc
what is a monocyte
agranulocyte; 3rd most common, 3-7%, rapidly leave circulation and mature into macrophage or dendritic cell
macrophage
largest phagocytes that ingest and kill foreign cells, wandering, motile, mop up messes, migrate out of blood stream, participate in specific immunity as an APC
dendritic cells
cells that have elongated pseudopods (dendrites); participate in specific immunity as an APC
APC
antigen presenting cell; will process foreign epitopes and display them among their MHC
what is a lymphoblast
lymphocyte forming cell
describe lymphocytes
2nd most common WBC, 20-30%; circulating WBC, cells involved in the specific immunity; agranulocytes
lymphocytes become what 2 cells
T cells and B cells
What are T cells
mature in the thymus; assist B cells and cause infected host cell apoptosis; cell mediated immunity (cell wars)
what is apoptosis
cell programmed death; tells cell to commit suicide
T cells can become what 4 types of cells
helper T cell, cytotoxic T cell, suppressor T cell, or memory T cell
describe B cells
mature in the RBM; differentiate into plasma cells and B memory cells to form antibodies in humoral immunity
describe natural killer cells
active against cancerous or virally infected cells
rubor
redness
calor
heat
tumor
swelling
dolor
pain
injury causes _____
injury–> vasoconstriction–> release of cytokines
vasodialtion causes
vasodilation–> increased blood flow–> increase vascular permeability–> leakage of plasma into tissues (exudate formation)
what is exudate
fluid that has leaked
edema
infiltration of site by neutrophils and accumulation of pus
histamines cause
cause vasodilation, vascular permeability, increase mucus production, release of mast cells
diapedesis
WBC migrate out of the blood into the tissue spaces
pus
whitish mass of cells, liquefied cell debris and bacteria
pyogenic
pus forming bacteria
what is + chemotaxis
phagocytes are drawn to the site of an injury by chemicals that are released by mast cells (mobilization)
phagosome
vesicle created by phagocytosis
what do granules release into the phagolysosome
reactive oxygen products: H2O2, O2-, OH-, and other powerful antimicrobial chemicals
phagolysosome
the combination of the phagosome and lysosome
lysosome
contain digestive enzymes
what are the metabolic changes that occur in a recently phagocytosis participating cell
switch to fermentation, create lactic acid, drops pH, digestive enzymes function at a higher level. The cell can then work at a 10x increase in effectiveness for the next victim
what 2 bacteria can hide in a WBC as an intracellular parasite
Mycobacterium tuberculosis and Salmonella typhi
what 2 bacteria are resistant to phagocytosis and whay
Staph aureus and Mycobacterium leprae are highly resistant because they produce many leukocidins
what are indogenous pyrogens and name 2
originating internally; released by monocytes in response to an endotoxin or interleukins released by T cells
interleukins
released by T cells
exogenous pyrogens
coming from outside the body. Ex: gram - endotoxin (The endotoxin itself causes the fever)
pyrogenic
fever causing
what are 3 benefits of a fever
speeds up everything: accelerate the response; inhibit growth of temperature sensitive microbes; impedes release of iron by macrophages and that affects bacterial nutrition
what is interferon (IFN)
small protein produced by WBC and tissue cells in response to viruses and cancer cells.
what can IFN inhibit
the expression of cancer genes and have tumor suppressor effects
what are complement proteins
consist of 26 blood proteins that work in concert to destroy bacteria and certain viruses
what are iron binding proteins
proteins that sequester iron in the body, making it less available for microbial nutrition
what are antimicrobial peptides
short proteins that insert themselves into prokaryotic membranes and kill the bacteria; might be the new age of therapeutic drugs (similar to antiseptics)
