Chapter 7 and 8: Immunity Flashcards
Antigens
markers on the surface of cells, they are proteins, so they must be transcripted and translated
Self Antigens
they can identify and recognise the cells of your body, so the immune system doesnt attack its own cells
Non-Self Antigens
The immune system reads these antigens as foreign meaning they get attacked
MHC Class I Markers
all cells with a nucleus in the body xpress MCH Class I markers,
MHC Class II Markers
found on specialised cells within the immune system, antigen presenting cells so they can present the pathogen to the T helper cells, the B cells and the cytotoxic T cells.
Pathogen
an agent that causes a disease and merits and immune response
Self and Non-Self receptors
B and T cells have these receptors on the surface that recognise the antigens as self or nonself `
Autoimmune diseases
when the immune system attacks against its own cells
Alergies
the response is initiated by the body recognising an antigen as non-self, which it launches a strong immune response too, the allergen isnt pathogenic and cannot cause the body harm, only the immune response can
First line of defence
- innate immune system
- physical barrier
- chemical barrier
- microbiological barrier
1st line of defence - Plants - Physical
thick bark, waxy cuticles of the leaves, formaltion of galls, presence of thorns and trichomes, ability to close and open the stomata
1st line of defence - Plants - Chemical
Chitinase, phenolds, defensins, saponins, oxalicacid and glucanases
1st line of defence - Animals - Physical
Intact skin
mucose secretion
1st line of defence - Animals - Chemical
lysosome in tears and saliva
acidic sweat
stomach acid
1st line of defence - Animals - Microbiological
bacteria on the skin, lower gastro intestinal
Second line of defene
non specific
happens simultaneously with the 3rd line of defence
faights all pathogens
Innate
- non specific
- quick response
- no memory
- short lived
Phagocytes
macrophage, dentritic cells, neutrophils
- non specific (eats everything)
- they engulf and destroy extracellular pathogens
- cleases cytokines wich help singal other cells about the pathogen
Phagocytosis
- phagocytes recognise (by antigens and receptor) the pathogens and engulf it
- the pathogen is enclosed in a vesicle called a phagosome, before it fuses with a lysosome, which releases lysozymes that break down the pathogen
Natural Killer Cells
eliminated intracellular pathogens
- undergoes degranulation, induces apoptosis
- large granulated cells
e
degranulation
- NK needs to identify the viral infected cells
- releases granzyme which are a type of protease to break down proteins
- perforin is releases to create pores on the surface of the plasma membrane f the infected cells
- granzyme enters the infected cells
- inducing apoptosis (controled cells death) via the intracellular pathway the mitochondrial pathways
NK - Killer inhibitory receptor
examines cells for MHC class I markers