The Human Immune System
PathogensOrganisms that cause disease
Nonspecific Defense
Two Lines of DefenseFirst Line of Defense and Second Line of
Defense
First Line of DefenseBarriers that helps prevent pathogens from
entering the body (skin, mucus, cilia, and stomach acid)
Second Line of DefenseLimit the Spread of Invaders
TypesInflammatory Response, Phagocytes, and Interferons
Inflammatory ResponseSwelling, Redness, Increased Warmth
increase blood supply to an area area gets more nutrients like
oxygen and white blood cells
Types Histamine and Body Temp
HistamineTriggers vasodilation (enlargement of blood vessels)
increases blood supply to area (also responsible for sneezing,
coughing, itchy eyes prevent pathogens)
Body TempIncreased Body Temp = harder for pathogens to
function
PhagocytesGobble up invading microbes
InterferonsChemicals released by the immune system to block
against viral infection
Specific Defense - Third Line of Dense
Third Line of DefenseBased off lymphocytes and antibodies
Types of LymphocytesB lymphocytes and T lymphocytes (both
originate in bone marrow)
SimilaritiesBoth recognize different specific antigens (germs
that triggers an immune response)
B lymphocytesProduce antibodies against a specific antigen
humoral response
T lymphocytesFight pathogens cell-mediated response
AntibodyAbility to bind to only one particular antigen
How do antibodies workNeutralize antigens b binding to them and
by forming an antigen-antibody complex that can then be gobbled up
a phagocyte
Clonal Selection
Clonal SelectionFundamental Mechanism in the development of
immunity
Plasma CellsFight antigens immediatly (primary immune
response)
Memory CellsFight the same antigens as plasma cells but remain
circulating the blood in small numbers for a lifetime
Immunological MemoryThe mechanism that prevents a person from
getting any specific viral infection more than once
Types of Immunity
Passive ImmunityTemporary antibodies are borrowed and do not
survive for long (breast milk)
Active ImmunityPermanent Organism makes antibodies itself Post
vaccine
ABO Blood Types
Danger in transfusionRecipient has antibodies to the donors
antigens
