Immune System 2 (chapters 7-8) Flashcards
Physical Barriers in Plants (1st LoD)
Bark
Waxy Intact Cuticle
Cellulose Cell wall
Thorns
Physical Barriers in Animals (1st LoD)
Intact Skin
Mucous Membrane
1st Line of Defence
Prevents entry of foreign mateial using physical and chemical barriers
Located on body’s surface
2nd Line of Defence
Non specific cellular and molecular responses to pathogens
Chemical Barriers in plants (1st LoD)
Peppermint oil - acts as antibacterial chemical
Citronella oil - Protects against fungi and bacteria
Mechanical Barriers (reflexes) (1st LoD)
Sneezing
Coughing
Vomiting
Diarrhoeia
Flushing Tears
Flushing Urine
Chemical Barriers in Humans (1st LoD)
Hydrochloric Acid in Stomach
Lysozyme in Tears
Microbiota barriers (1st LoD)
‘Microbes’ in the gut
exist in mutualistic relationship with person
prevent growth of colonies of other bacteria by outcompeting for nutrients, adhesion sights and secreting antimicrobial chemicals preventing growth of pathogenic bacteria
In return, the immune system tolerates their presence
Attenuated Vaccines
Whole Pathogen Vaccine
Contains whole bacteria or virus weakened through genetic modification or other means
- Can reproduce (unless virus)
Deactivated Vaccines
Whole Pathogen Vaccine
Contains whole bacteria or virus which has been killed so it CANNOT reproduce
mRNA Vaccines
Nucleic Acid Vaccine
Use RNA in a lipid membrane.
The RNA, once inside a cell, enters the ribosome, where it is ranslated to make the protein
Innate Immunity
Non Specific Immunity
1st and 2nd Line of Defence
Same for all infections
No ‘Memory’
Inflammation Symptoms
Physical condition
Reddened, swollen, hot painful reaction to injury/infection
Inflammation followed by discharge of pus
Inflammatory Response
- Blood vessels in the area around the damaged tissue dilate, causing an increase in blood supply to the area. (Vasodilation)
- The blood carries phagocytes to the area. Phagocytes also come from interstitial fluids surrounding the damaged tissue.
- Phagocytes release cytokines into the damaged tissues, which attracts more phagocytes to the area.
Macrophages
Engulf bacteria
Use cytokines to signal other Phagocytes to attack bacteria
Neutrophils
Respond to cytokines
Use phagocytosis to engulf bacteria
Main producer of pus
Mast Cells
Cause vasodilation - making cells bigger
Dendritic Cells
Produce antigen material and present it on cell surface to other cells in the immune system
Act as messengers between innate and adaptive immune systems
Initiate Immune Response
Eosiniphils
Granulocytes that are present in the respiratory, gastrointestinal and urinary tracts
Assist in defending against larger parasitic agents that are too large to be phagocytoses
Contain granules with toxic chemicals and histamine
Upon contact with pathogen, degranulation results in toxic chemicals being released.
Natural Killer Cells
Lymphocytes that kill virus infected body cells or tumour cells
Release toxic granules into abnormal cells to kill them
Cytotoxic (Cell Killing)
Complement Proteins
Made in liver, circulate bloodstream inactively
When activated:
- Attract Phagocytes
- Mark bacteria for destruction (Phagocytosis)
- Form cell destroying Membrane Attack Complex (MAC)
Interferons (INFs)
Signalling molecules released from virus infected host cells
- Cause nearby cells to heighten antivirus defence
- Cells stimulated by INFs prouce various enzymes to inhibit protein synthesis
Self Antigens
From within the body
Tolerated by the immune system
Non Self Antigens
From external environment
Identified as invaders and attacked by the immune system
Cellular Pathogen
microorganisms that are composed of cells
Bacteria
Fungi
Worms
Protozoa
Non Cellular Pathogen
microorganisms that are not composed of cells
Prions
Viruses