Cell recognition and the immune system Flashcards
How do white blood cells help defend against pathogens?
White blood cells:
- ingest pathogens
- produce antitoxins which destroy particular bacteria or viruses
- produce antitoxins that counter toxins released by pathogens
What’s the definition of a pathogen?
A disease causing micro-organism is a pathogen 🦠
How do vaccines work (basic)
Vaccines introduce small quantities of dead or inactive forms of the pathogen into the body. This stimulates white blood cells to produce antibodies that destroy the pathogens
What is a phagocyte?
Phagocytes are cells that can invest then digest microscopic pathogens.
What is a lysosome?
Lysosomes are substances in the cytoplasm that contain enzymes called lysozymes and help destroy ingested pathogens.
What is the second line of defence to a pathogen?
The second line of defence is the non-specific response
What is a non-specific response?
The non-specific immune system involves defences that are general and ongoing. Skin, parts of the lungs, and stomach are mechanical barriers. After the pathogen enters the body, non-specific cells like macrophages attack and ingest the pathogens, and natural killer T-cells attack the pathogen directly.
What are self antigens?
You’re own cells
What are non self antigens
Virus’s
Bacterium
Cells from other people
What is an antigen?
A large foreign molecule that stimulates an immune response
What is the difference between phagocytes and lymphocytes?
Phagocytes are non specific and they ingest and destroy any and all microscopic pathogens. In contrast lymphocytes are specific and only attack one type of antigen
What are the two types of lymphocytes?
B lymphocytes
T lymphocytes
What do B lymphocytes do?
B lymphocytes mature in bone marrow and release antibodies into the blood
What do T lymphocytes do?
T lymphocytes mature in the chest of thymus and cause a cellular response to infection. They do not release antibodies into the blood
