Immune Response and Defence Against Disease Flashcards
What are antigens and what do they do?
Antigens are molecules presented on the surface of the plasma membrane of cells capable of producing an immune response. They act as recognition sites for the immune system
Define innate immunity
responses are non-specific and do not create immunological memory. This includes the first and second lines of defence.
Define adaptive immunity
responses are specific and involve immunological memory. It involves the third line of defence.
What is in the 1st line of defence for plant?
- Chemical Barriers (e.g. toxins)
What is in the 2nd line of defence for plants?
- Production of proteins and enzymes that provide defence against pathogens
What are the 1st line of defence for animals?
- Surface barriers (e.g. skin and mucus membranes)
- Chemical secretions
What is the 2nd line of defence for animals?
- Phagocytic leukocytes
- inflammatory response
- Antimicrobial proteins
- Fever
What occurs during the inflammatory response?
After tissue injury:
- Capillary widening → increased blood flow → heat
- Increased permeability → fluid release into tissues → redness and swelling
- Attraction of leukocytes → extravasation of leukocytes to site of injury → tenderness
- Systemic response → fever and proliferation of leukocytes → pain
Summarise what the inflammatory response is
During the inflammatory response there is an accumulation of fluids, leukocytes, cytokines, histamine and plasma proteins where tissue is damaged or infected.
This results in swelling, redness, heat and pain.
What is the difference between active and passive immunity?
Active immunity involves antibodies produced by the body itself and so memory cells are developed whereas passive immunity acquires antibodies from another source and so memory cells are not developed.
How do vaccinations create immunity?
Vaccinations introduce an antigenic material into the body that allow the body to produce antibodies for the disease without the body being in danger.
This means that if the body comes in contact with the disease, it can be identified from the memory cells and antibodies can be produced
What is the 3rd line of defence?
The final line of defence are the lymphocytes that produce antibodies to specific antigenic fragments
What do B cells do?
B cells produce specific antibodies, there are millions of different B cells in the body capable of detecting difference antigens.
What are T cells?
Helper T cells regulate B cell activation, ensuring antibodies are only produced when appropriate
What is the role of the compliment system?
The compliment system works as the mediator of the innate immune response, contributing to cell homeostasis, tissue development, and repair, reproduction, and cross-talk with other endogenous systems.
