Lecture 3 Flashcards
immunity
collection of mechanisms that defend human body against disease
Lymphoid System
- immunological defense
lymph nodes
filter bacteria and viruses from fluid; filtration units deal with antigens localy
lymphocytes
T + B cells
lymph nodes
aggregation of lymphocytes/T+B cells
thymocytes
T cells in thymus
parenchyma
cellular component of the thymus
stroma
supportive/connective elements of the thymus
lobules
compartment of the lobe
T helper cells
- CD4 marker
- MHCII
- boost immune response
cytotoxic T cells
- CD8 marker
- MHCI
- eliminates infected/tumour cells
double positive
cells with both CD4 and CD9 markers
mast cells
- release bioactive chemicals
- trigger accute inflammation
neutrophils
- signals other cells
- eats and digests pathogens
- 70% of WBC population = most abundant
macrophages
- stimulate other immune cells (lymphocytes and fibroblast)
- eats and digests pathogens, cellular debris
Pathogen Associated Molecular Patterns (PAMPs)
parts of bacterium of cells/viruses that are recognized by the phagocyte
(ex. LPS, Flagellin, Lipoteichoic acids, peptidoglycan, ds/ss vRNA, bacterial DNA, repeating structural units
Pattern Recognition Receptors
on phagocytes … (NEED MORE ON THIS)
- recognize PAMPs
1) C-Type Lectin receptors (CLRs)
2) Toll-like receptors (TLRs)
3) NOD-Like Receptors
4) RIG1-Like Receptors
chronic inflammation
- more variable than acute
- several forms of tissue reactions over long period of time
frustrated repair
?
exudation
leakage of fluids
resolution
return of injured tissue to normal structure and function
- when injury not extensive and parenchyma are capable of regenerating
- alternative — fibrous repair
granulation
process where initial blood clot converted into fibrous connective tissue
antigen
foreign body; epitope — region that reacts with an antibody, TCR, SIGs
antibodies
immunoglobulin (Ig) marks antigens for elimination
IgM
stops infection by toxins and viruses
IgG
- main one
- protects newborns by crossing placenta
IgA
defence of mucosal surfaces
IgE
allergy/hypersensitivity reaction
IgD
triggers B lymphocytes
macrophages
engulf foreign bodies
B cells (—> plasma cells)
produce antibodies
Effector Helper T cells
interleukins
Effector cytotoxic T cells
perforans
autoimmunity
immune system attacks “self” cells
- when negative selection does not work 100%
hypersensitivities
immune system over reacts with secondary exposure to an antigen
immunodeficiencies
immune system under reacts
