Q3 Immunity Flashcards
What is the name of the two immunities animals have? describe it
Innate –> given by birth and genetically determined, includes 1st and 2nd line of defence.
Adaptive Immunity –> Activates when the 1st and 2nd defences are breached –> acquired (built over time) –> Targets specific pathogens
Go in order the lines of defence, stating whether they are innate of adaptive
1) First line of defence (innate) e.g) skin
2) Second line of defence (innate) e.g) Leukocytes (white blood cells)
3) Third line of defence (adaptive) e.g) B and T cells
Describe the First line of defence (innate) and name some physical & chemical features
Non specific response which, including physical & chemical barriers –> stops growth and entry of pathogens
Physical Features
1) Mucus membranes: traps antigens/pathogens, contains lysosomes
2) Cilia: tiny hairs that line the airway –> sweeps back and forth –> cough or sneeze
3) Skin: ph 5-6 (too acidic for pathogen)
4) Other: Vomiting, Diarrhoea, Increased urination, Wound healing
Chemical Features
1) antimicrobial enzymes or Ph levels to kill pathogens –> e.g) stomach acid, bile, urine, sweat, saliva and tears
Describe the Second line of defence (innate) –> What are the reactions (there are 3)
Non specific, activates when the 1st line of defence fails includes different types of white blood cell (Leukocytes)
E.g) Neutrophils, Macrophages, plates
–> reactions include inflammation, phagocytosis and interferons
In the second line of defence (innate), Describe inflammation
Cell releases histamines and prostaglandins –> cause blood vessels causing vasodilation
Increase blood flow to the side, induces heating, redness and swelling → carrying with it white blood cells (Phagocytes) to attack pathogens
In the second line of defence (innate), Describe Phagocytosis?
Phagocytes (neutrophiles & Macrophages) engulf and destroy pathogens
–> this is defence mechanism to enclose a non-specific pathogen –> they release lysosomes destroys pathogens
Minimises impact before the adaptive immune response, phagocytes may present antigens activating lymphocytes
In the second line of defence (innate), Describe Phagocytosis?
Infected cells, secrete proteins called interferons
–> calls neighbouring cells to produce chemicals to reduce viral particles which is necessary to propagate a virus infection.
–> also may signal cells to perform apoptosis
Describe the Third line of defence (Adaptive) –> What are the reactions (2)
activates when the snd line of defence fails, specific and has memory cells (stay in the body forever), two responses
–> Humoral response: B cells, pathogen outside cell
–> Cell mediate response: T cells, pathogens inside cell
