Compendium 11 - How do we protect ourselves Flashcards
differentiate between the immune system and the lymphatic system
the immune system (active) - contains the proteins, cells, tissue, organs to fight a pathogen
the lymphatic system is the stansport system for the cells of the immune system
define a pathogen
a foreign agent presenting non-self antigens
can be parasites, bacteria, fungi, protozoa
what does the immune system fight against
- foreign substances and internal threats (own cells presenting antigens wrong eg. cancer cells)
what are the components of innate immunity
first line of defence = physical barriers
second line of defence =
- white blood cells (phagocytes)
- inflammation
- chemical mediators
- fever
what are the two types of of adaptive immunity (and what cells do they involve)
- cell mediated immunity (T cells)
- antibody mediated immunity (B cells)
what are 3 characteristics of innate immunity
- non specific
- present at birth
- no memory
what are some examples of physical barriers (in innate immunity) (7)
- skin
- mucous membranes
- saliva
- tears
- acid
- urine flushes
- cillia
What are 4 chemical mediators of the innate/nonspecific immune response and what do they do
histamine - vasodilation, increase vascular permeability, attract WBCs
cytokines - activate t cells, initiate phagocytosis and inflammations,
secreted by cells to stimulate neighbour cells, regulate duration and intensity of response
complements- stimulate lysis
interferons - antiviral (restricts replication and alerts adaptive immunity branch)
what are the 5 types of WBCs and what is the role of each
neutrophils - often the first responder, phagocytosis, acute inflammation
macrophages - phagocytosis, repair, activate B and T cells
Basophils - produce histamine, immunosurveillance
Eosinophils - respond to parasitic infection and allergy
Natural killer - lysis of viral infected cells and cancer cells
what is inflammation and why are the symptoms caused
- it is the localised response to tissue damage (pathogens or injury)
redness + heat (due to increased blood flow)
swelling (increased permeability = more fluid leaves capillaries)
pain ( increased fluid pressure stimulates nerve endings)
what is fever and what is the effect of rising temperature on the body
- generalised response to damage/infection
increased temp results in:
- an increase in antimicrobial substance / augmented performance of immune cells
- decrease microbial growth
- speed up body reactions to help tissue repair
what is the role of MHC class 1
it is a pathway that puts peptide fragments from inside a cell on the surface as antigens, so other cells can recognise if its a normal cell or not
- eg. if infected with a virus, viral proteins will be put out as antigens and alert other cells that it is infected
what is the process of cell mediated immunity
- T cell receptors recognise specific viral protein
- Cytotoxic T cell divides into 2 daughter cells ( if helper t cell helps, via interleukin-2)
- daughter t cells can now kill any cell with that antigen
what is the process of antibody mediated immunity
- WBC phagocytosis of antigen + express the antigen on their surface
- helper t cell binds to it + secretes interleukin (if it recognises/confirms it is a bad antigen)
- interleukins stimulate B cells to devine and produce antibodies
what are the 2 types of B cells
plasma B cells - make antibodies
memory cells
what are the 3 effects of antibodies
- inactivate antigen by binding to it
- bind antigens together
- facilitate phagocytosis (bigger complex - easier to get)
what do memory cells do during a secondary response
- divide rapidly to form more plasma cells and memory cells (causing a faster and greater response)
how long is a first response and secondary response to an antigen
first response - 3 to 14 days
second response - hours to a few days