Immunity Flashcards
Which blood cell is the main fighting factor in the immune system?
White blood cells
What is the name of a disease-carrying micro-organism and give an example
A pathogen, bacteria e.g. e-coli, which can cause gastrointestinal infection and diarrhoea or the HI virus which can cause AIDS
What do pathogens excrete and how can they damage the body?
Toxins can be released, they can poison the body
What is the first line of defence against pathogens
The skin layer
What are the two main types of white blood cells?
Lymphocytes e.g. T cells and B cells and phagocytes e.g. neutrophils
What do phagocytes do?
They engulf and digest bacterium in a process called phagocytosis
How is phagocytosis done?
1.Phagocyte recognises pathogen
2. Phagocyte engulfs pathogen in a process
known as phagocytosis
3. The lysozymes containing enzymes
move towards the pathogen
Enzymes break down pathogen
5. Useful materials are absorbed
6. Waste products are removed from the
phagocyte
What do lymphocytes do?
Lymphocytes produce antibodies, which are proteins that attach to a pathogen via the antigen.
How does the lymphocyte help the immune system and combat pathogens
- Lymphocytes detect pathogen
- They then produce many different types of antibodies
- Correct antibody connects to the pathogen’s antigen
- Lymphocyte releases large number of
correct antibody - Pathogens either clump together resulting
in death or the antibodies trigger phagocytes.
Some pathogens can even burst.
Some antibodies are specialised to combat
toxins they are called anti-toxins - Lymphocytes produce cells that produce
that antibody very quickly, These are called
memory cells.
What else do lymphocytes produce apart from antibodies
They produce memory cells
How long do memory cells last?
They can last a lifetime
What do memory cells do?
They remember which antibody to produce for which pathogen, producing antibodies more quickly than before, increasing the speed and efficiency at which the immune system reacts to the pathogen
How do vaccines work?
This dose is either; the dead pathogen or parts of the pathogen’s cell surface. This stops the pathogen from causing a disease.The lymphocytes generate antibodies against the pathogen and more importantly, make memory cells. This way, vaccines can give us immunity.
