Immunity Flashcards
What is immunity response?
Is the way an organism protects itself against pathogenic viruses, bacteria, Protozoa or fungi
The immune system monitors…
The immune system monitors the constant exposure to harmful elements and provides defence.
What are the two main categories that the immune response is decided into?
- Innate immunity
- acquired immunity.
What’s the difference between acquired immunity and innate immunity?
Natural immunity:
● Present from birth
● First line of defence
● Non-specific
● Can destroy different pathogens
Acquired immunity:
● Developed through exposure to pathogens
● It works when the natural immunity is penetrated
● White blood cells destroy the pathogens and prevent re-infection
What is the first line of defence in humans?
-Skin
-coughing and sneezing
-tears and mucus
What is the second line of defence in humans?
-Inflammation and fever - prevent the multiplication of pathogens
Where do antigens occur and why?
Antigens occur as markers on the surface of all body cells, viruses, bacteria, protozoa and fungi.
What are the scientific names for white blood cells and red blood cells.
White blood cells - leukocytes
Red blood cells - erythrocytes
What happens when a foreign pathogen enters the blood stream?
Leucocytes instantly recognise the pathogens as foreign cells then destroy or neutralise the pathogen.
What are the two main types of leucocytes that play a role in active immunity.
- lymphocytes.
-phagocytes.
Where do the lymphocytes occur and what percentage of all blood cells do they make up?
- They occur in the lymph nodes, spleen and blood vessels.
- they make up 20 to 40% of all blood cells.
What are the two different types of lymphocytes?
T - lymphocytes
B - lymphocytes
What do B-lymphocytes do when a pathogen is recognised as foreign?
-B-Lymphocytes multiply and produce antibodies.
When antibodies bind to antigens what does this cause to happen.
- Mark them for indigestion of phagocytes
- make them bond together which causes them to be inactive.
- cause the pathogens to burst
What do T-lymphocytes do?
They recognise and destroy the infected body cells.
Why can’t antibodies reach viruses?
Viruses hide in host cells which is why antibodies can’t reach them.
What part of T - lymphocytes recognises foreign viruses ?
Receptor proteins on the T-lymphocytes
How do T-lymphocytes destroy cells?
They secrete chemicals or cause them do burst.
What’s another name for CD4-cells and what do they do?
- T - helper cells
- help other T-lymphocytes by initiating an immune response against infection.
What will happen is the body is infected with the same virus?
When body is infected by the same pathogen these cells will multiply faster and react faster due to the B- and T- lymphocytes.
Where are phagocytes produced and whatsoever they look like?
- phagocytes are produced in the red bone marrow
- large white blood cells that can change shape
What happens during phagocytosis?
Phagocytes engulf pathogens killing and degrading them.
