B5.9 Human defence responses Flashcards
How does your skin act as a barrier?
Your skin covers your body and acts as a barrier - it prevents bacteria and viruses reaching the tissue beneath
What happens when you damage or cut your skin?
The barrier gets broken but your body restores it. You bleed and the platelets in your blood set up a chain of events to form a clot that dries into a scab.
What does a scab do?
Forms a seal over the cut - stopping pathogens getting in
What does your skin do destroy bacteria?
Produces antimicrobial secretions to destroy pathogenic bacteria
Healthy skin is covered with microorganisms that help keep you health and act as an extra barrier to the entry of pathogens
What is the benefit of your nose being full of hairs and producing mucus?
The hairs and mucus traps particles in the air that may contain pathogens or irritate your lungs
Why is the lining of the tubes is covered in cilia?
Tiny hair like projections from the cells - beat to waft the mucus up to the back of throat
where it is swallowed
What does the stomach produce to destroy microorganisms?
Acid to destroy the microorganisms in the mucus you swallow as well as the majority of the pathogens you take in through your mouth in your food and drink
What are the three ways your antibodies destroy the pathogens that has entered your body?
Ingesting microorganisms
Producing antibodies
Producing antitoxins
How does phagocytosis protect you against diseases?
Some white blood cells ingest pathogens - digesting and destroying them so they cannot make you ill
How do antibodies prevent diseases?
Antibodies target particular bacteria or viruses and destroy them - you need a unique antibody for each type of pathogen
What are the benefits if your white blood cells know how to produce antibodies against a particular pathogen?
They can be made very quickly if that pathogen gets into the body again
How does antitoxins prevent diseases?
Some white blood cells produce antitoxins - these counteract the toxins released by the pathogens
