elements of immune system Flashcards
strep throat
1) streptococcus pyogenes
2) fever
3) throat becomes
- erythematous
- swelling
- pain
- dysfunction
inflammation
1) one of the two principal types of reactions mediated by innate immune system
2) chronic inflammation is bad
major function immune system
1) homeostasis
2) distinguish self from non self
3) immune responses arise as a result of foreign stimulation
removal of virus infected cells by CD8+ (cytotoxic T cells)
1) MHC-class 1 are self component
2) a virally infected cell will present viral fragment on MHC1
- CD8+ comes in contact and kills it
macrophages and neutrophils
1) encounter non self and phagocytose them
neutrophil extracellular trap
1) neutrophils can shoot traps to catch pathogens
acceptance of nonself
1) high fetal HLA-G expression
2) maternal does not attack fetus
- trophoblasts in placenta express universal HLA-G
—
1) bacteria and food in GI tract and oral cavity
2) immune tolerance
- non responsiveness to harmless foreign bacteria
hypersensistivity
1) overreaction of immune response
autoimmune disease
1) immune system attacks the self
2) benign mucous membrane pemphigoid and sjogrens syndrome
- women are more susceptive to AI disease
most important physiologic function of the immune system is
1) to prevent or eradicate infections
innate immunity
1) initial defense against infections
2) non specific
- structures common to groups of related microbes
3) no memory
adaptive immunity
1) 12 hours after initial infection
2) humoral
- antibodies produced by B cells
- extracellular microbes
3) cell mediated
- T cells (T lymphocytes)
- CD4+ and CD8_
- intracellular microbes
clinical features of adaptive
1) eliminate organisms more efficiently
why does adaptive immunity have specificity and memory
1) clonal selection theory
2) lymphocytes epcific for large number of antigens exist
- when it enters, it selects the specific cell and activates them
3) some of them become memory cells
active immunity
1) our own immune system is responsible for protecting against a pathogen
2) generates antibodies in days to weeks
3)
passive immunity is
1) immunity gained by transferring Igs from someone else
2) naturally occurring
- maternally acquired
3) artificial
- manufactured Abs or Abs from immune individual
immune system have two levels of defense
1) skin and immune barrier
2) cells and soluble molecules in innate system
3) activation of adaptive system by innate system
4) cells and products of the adaptive system reinforce innate system
epithelial barriers
1) skin and mucosal tissue
2) interface with outer environment
3) limit microbial entry
4) killing microbes with residential lymphocytes and antimicrobials
antimicrobial peptides
1) broad spectrum of activity
2) small cationic and amphipathic
- cancel charge of bacteria
3) direct disruptions of bacterial cell membrane
- create hoels
4) antimicrobial and chemotactic
intraepithelial lymphocytes
1 )tissue resident cells that produce cytokines similar to those secreted by helper T lymphocytes
2) do not express T cell antigen receptors (TCRs)
3) unknown mechanism of how they kill microbes
polymorphonuclear leukocytes
1) PMNs
2) neutrophils
- 70% of leukocytes
- multilobed
3) granules: primary, secondary, and tertiary
4) phagocytosis
lysozymes
1) muramidase
2) impair structure of peptidoglycan
- break 1,4 beta linkages between NAM and NAG
basophils and eosinophils
1) parasites?
mononuclear phagocytes
1) monocytes in circulation
2) macrophages
- bone marrow derived macrophages
2) tissue resident macrophage
- derives from cells in yolk sac
- organs like liver (kupffer), spleen (splenic macrophages), lung (alveolar macrophages)
mast cells
1) cytoplasmic granules
2) allergic and parasitic infection
dendritic cells
1) spleen, lymph nodes, thymus, skin/mucosa
2) phagocytic
3) most potent APCs
4) present antigens to T cells
- activation of adaptive immunity
natural killer cells
1) derived from lymphoid cells
2) roles in both innate and adaptive
- in innate, eliminate malignant cells and secrete cytokines and IF gamma
B cells
1) B cell antigen receptors
- BCR engagement by antigen results in differentiation to plasma cells
2) plasma cells
- produce antibody
T cells
1) naive T cells
- CD8+ and CD4+
primary lymphoid organs
1) bone marrow for B cells and thymus for t cells
secondary lymphoid organs
1) activation of B and T cells
- spleen, lymph nodes, peyers patches
