The Immune System And Fighting Disease Flashcards
Name non 4 specific defences that prevent pathogens from entering the body
Skin (acts as a physical bartrier and it it secretes oils e.g sebum that repules pathogens).
Stomach Acid - kills pathogens that make it far from the mouth from its low pH
Hair and mucus - trap pathogens
Tears in eyes - are antiseptic and mill pathogens
Platelets form scabs
How does the human body defence act against pathogens
The skin- Acts as a physical barrier, secretes sebum which is an oil like substance that repels pathogens.
Stomach Acid- hydrochloric acid creates a low pH that destroys pathogens in food or drink
Hair and mucus - produced by cells that line the trachea and bronchi) traps pathogens. Cilia help to then move the mucus and pathogens up and out the lungs
Tears in eyes - are antiseptic and contain chemicals to kill pathogens
Platelets- form scabs/clots to stop pathogens from entering
What is the role of the immune system
To locate and destroy pathogens that enter the body + any toxins they produce. The immune system also protects us incase the same pathogen invades us again in the future.
What type of cells help defend against pathogens and are the most important part of the immune system
White blood cells
What are the 3 main functions of white blood cells
- Phagocytosis
- Producing antibodies
- Producing antitoxins
Describe the process of phagocytosis in 1 sentence
Phagocytosis is the process by which a Phagocyte tracks a pathogen down, binds to them then engulfs and destroys them.
What are the steps of phagocytosis
- First, the phagoctye tracks down a pathogen and binds to it.
- The Phagocyte’s membrane will then surround the pathogen and engulf it.
- Finally enzymes inside the Phagocyte break down the pathogen in order to destroy it
What is an antigen
An antigen is any substance that your body sees as foreign, which thn causes your immune system to produce antibodies against it.
E.g. the toxins and cell walls of pathogens
White blood cells produce antitoxins.
What are antitoxins
Antitoxins are small proteins produced by white blood cells that bind and neutralise the toxins produced by bacteria so they can’t do any damage.
What Is the difference between an antigen and a antibody
An antigen is a substance that your body sees as foreign, which then causes your immune system to produce antibodies against it.
An antibody is however a protein produced by our white blood cells that bind to specific antigens. This acts as a signal to our immune system to destroy the antigen
What do antibodies bind to
Antibodies bind to antigens that have a complimentary shape
What is an antibody
Antibodies are proteins produced by white blood cells, that can lock on/ bind to the antigens and group them all together then act as signals to tell our white blood cells to come and destroy/engulf them all in one day2
2 features of antibodies
Antibodies are very specific e.g. if a person catches measles they will only develop anti body’s for the measles virus and not any other pathogen.
Secondly antibodies can remain in the blood for a very long time, this means they can protect us if we ever get infected again with the same pathogen
