Intro to Immunology Flashcards
What is Immunity?
The capacity to distinguish foreign from self
What makes up the haematopoietic system?
Organs involved in the production of blood:
Spleen, Bone Marrow, Lymph Nodes
What is the immune system?
A system of organs and processes that protect the organism from disease
What is the lymphatic system?
A network of lymph vessels and nodes involved in antigen capture and transport
What does a mast cell do and where is it found
Mast cells dilate blood vessels and induces in the inflammatory response by histamine. It also Attracts macrophages and neutrophils.
It is found in the connective tissue and mucous membranes
What does a macrophage and where is it found?
Consumes foreign and pathogenic material
It is found in the blood vessels but can migrate to tissues
What does an NK cell do and where is it found?
It kills tumour cells and cells infected with viruses
Circulates in the blood but can migrate to tissues
What does a dendritic cell do and where is it found?
Present antigens to trigger an immune response
Present in epithelial tissue, migrates to the lymph nodes after activation
What does a neutrophil do?
The first responder at a site of infection or trauma, it is the most abundant phagocytotic cell type
What does a basophil do?
Defends against parasites, uses histamines to cause inflammation (may cause allergic reactions)
What does an Eosinophil do?
Defends against bacteria and parasites by using toxins, but also causes tissue damage
What is an immune response?
A reaction to something that appears foreign or harmful
What happens when Pattern Recognition Receptors (PRR) are engaged by Pathogen Associated Molecular Patterns (PAMPs)?
Intracellular pathways are stimulated causing the secretion of inflammatory modifiers
What are PRRs?
Pattern Recognition Receptors, the are innate immune receptors
How does phagocytosis occur?
- Microbe binds to PRR which activates phagocytosis
- Membrane internalizes the microbe causing a vacuole known as a phagosome to form
- Lysosome containing enzymes fuses with phagosome to form Phagolysosome
- Microbe is digested
All nucleated cells have MHC class____
1
Dendritic cells, B-cells and mononuclear Phagocytes have MHC class____
2
CD8+ (Cytotoxic) T-cells respond to MHC class____
1
CD4+ (Helper) T-cells respond to MHC class____
2
What is an immune response?
A reaction to something that appears foreign or harmful
What is a Kupfer cell?
A type of macrophage found in the liver
What is an osteoclast?
A type of macrophage found in the bone
What is a Microglia?
A type of macrophage found in the brain
What is a Mesangial cell?
A type of macrophage found in the kidney
How are antigens presented?
The microbe is processed and antigenic peptide fragments are presented on cell surface bound MHC molecules
What are DAMPs?
Damage-Associated Molecular Pattern responses
Some innate receptors can be activated by damage to the cell
What is opsonisation?
The process by which a foreign cell is made more susceptible to phagocytosis.
Antibodies coat the foreign cell making it easier to eat
What is a Phagosome?
A vacuole formed by the internalisation of the cell membrane bound foreign particle
What is a Lysosome?
A membrane bound packet of lytic enzymes (Lysozymes)
What are Lysozymes?
A lytic enzyme, it is the major secretory component of macrophages
What is a Pagolysosome?
A sac created by the fusion of a Phagosome and Lysosome in which microbes are killed and digested
In the MHC class 1 pathway what happens?
- Virus infects a cell
- Cell uses proteases to digest the virus’ products (viral cytosolic proteins)
- Cell displays the cytosolic proteins on it’s MHC I molecule
- CD8+ cytotoxic T-cell recognises this and kills the cell
In the MHC class 2 pathway what happens?
- Bacteria is phagocytosed
- Bacteria is destroyed in Phagolysosome
- Proteins from the bacteria are present on MHC II molecule
- CD4+ (Helper) T-cell comes and initiates a B-cell response
Viruses create an __________ source of antigen and therefore they are involved in the MHC class __ pathway
Intracellular source
2
Bacteria create an __________ source of antigen and therefore they are involved in the MHC class __ pathway
Extracellular source
1
Myeloid cells are involved in the ________ response
Innate
Lymphocytes are involved in the ________ response
Adaptive
What are the 4 features of cross-talk between the innate and adaptive cells?
Opsonisation of the cells invading
Complement binding
Presentation of antigens
Help - Helper T-cell help needed to create antibodies
The binding of ______ to an antigen increases it’s ability to iniate a ________________________
Complement
Strong and lasting B-Cell response
What is immunodeficiency?
Deficits or defects in the immune system resulting in the inability to respond.
Can be genetic (Primary) or due to medications/nutrition (Secondary)
What is hypersensitivity?
Overreaction or out of proportion reaction to damage caused by a pathogen or a reaction to a harmless antigen such as food or pollen
What is autoimmunity?
Immune reaction to self antigens
What is immunosupression?
The reduction in activation or the ability to produce a desired response of the immune system
