physiology -immunity Flashcards
the role of the immune system :
- defends the body against pathogens
- removes worn out cells
- destroys abnormal / mutant cells in body
immunes systems harmful effects
- allergies / autoimmune diseases
2. tissue rejection
Infection-causing organisms (Pathogens)
bacteria
fungus
parasite
virus
classification of tissues in the immune system
primary (central) lymphoid tissues
secondary ( PERIPHERAL) lymphoid tissues
primary lymphoid tissues
bone marrow - site of b cell develpoment
thymus - site of t cell develpoment
secondary lymphoid tissues
spleen appendix lymph nodes tonsils adenoids gut associated lymphoid tissues (GALT) peyers patches
neutrophils:
commonness
functions
most abundant leukocyte (60-70%)
destroy bacteria by phagocytosis
first defenders for bacterial invasion
eats up cell debris
what is phagocytosis
when phagocytes ingest or engulf cells / particles
eosinophils
how do they increase
function
commonness
allergic conditions eg asthma or hay fever
stop internal parasite infestations eg worms
1-4% of leukocytes
monocytes…life span
emerge from bone marrow while immature , circulate for a day or two before settling down in various tissues in body
the mature and enlarge in their tissue and become macrophages
they then become professional phagocytes and act as antigen cells
what is a macrophages
means large eaters
life span of several months to years
Organisation of the immune system
specific(adaptive) …antibodies
non specific immunity (innate). ….. identifying cells and eating them
examples of non specific immunity
phagocytsis , inflammation
what is innate immune response
initial and immediate response against invasion of any pathogens
main mechanism of innate immune response
- physical barrier (skin,mucous membrane )
- inflammation and phagocytosis
- interferon , natural killer cells
- complement
Specific (Adaptive)
examples
when does it happen
response
lymphocytes
after nonspecific responses happen
specific pathogens on 2nd or later exposure
The goals of the inflammatory response are to:
prevent initial infection or remove any damaged tissue
prevent spread of infection or repair any damaged tissue
mobilize effector cells T and B lymphocytes
results of Inflammatory Response
destroys or inactivates invaders
.removes debris
prepares for healing and repair
signs of Inflammatory Response
redness
heat
swelling
pain
stages of Nonspecific— Phagocytosis
attachment
internalisation
degradation
exocytosis
what is attachment
the macrophage will recognize invading pathogen and it will attach itself onto it
internalisation
macrophages then internalise pathogen , which forms a phagosome ( an structure in the macrophage that the bacteria are contained within) that allows the macrophage to digest the invading bacteria
what is interferon
cytokine release by virus infected cells
