L10 - immune system overview Flashcards
What is the immune system?
A network of cells and tissues constantly patrolling our body for invaders
What are some types of pathogens?
Viruses, intracellular/extracellular bacteria and parasites, extracellular parasitic worms
What are the four phases of the immune response?
- Establish infection
- Inductive phase
- Effector phase
- Memory phase
Name the primary and secondary lymphoid organs
Primary: foetal liver, thymus, bone marrow
Secondary: lymph nodes, spleen, Peyer’s patches, adenoid, tonsils, appendix
What is innate immunity?
The first line of defence
Immediate and local, not specific for pathogens and therefore has no memory response
What is adaptive immunity?
Defence mech used 7 days after initial encounter with pathogen
Systemic and specific for the antigen - has a memory response
What is the role of cytokines?
Cause release of compounds that increase activity of leukocytes, increase acute phase proteins and neutrophil motility
give examples of granulocytes
Neutrophils, eosinophils, basophils
Give examples of APC cells
Monocytes/macrophages, dendritic cells, B cells
What is the last class of immune cells? give examples
Natural killer cells e.g. T cells
Spontaneous killing via perforin and granzyme B
Have R that both activate and inhibit them - to survive a cell must activate both
What is the complement system?
Part of the innate immune system that enhances the ability of antibodies and phagocytes to clear microbes from the body, promotes inflammation and attacks the pathogens cell membrane
What makes up the complement system?
A small number of proteins that are synthesized in the liver and found in the blood. They circulate as precursor proteins
What activates the complement system?
The classical complement pathway, the alternative complement pathway and the lectin pathway
What immune functions are triggered by the complement pathway?
Phagocytosis, inflammation and membrane attack
What are the components of the tumour microenviroment?
ECM, stromal cells and tumour cells - chronic inflam, immunosup, pro-angio
