Human Defence System Flashcards
What 4 features does the human body have that fights against pathogens
- Skin
- Hairs and mucus
- The trachea and bronchi
- Stomach
How does skin defend
acts as a barrier, it also secrets antimicrobial substances which kill pathogens
How does hair and mucus defend
in your nose trap particles that contain pathogens
How does the tranchea and bronchi defend
secrete mucus to trap pathogens and are lined with cilia (hair) which waft the mucus up to the back of the throat where it can be swallowed
How does the stomach defend
produces hydrochloric acid, this kills pathogens
How does the immune system attach pathogens
If a pathogen enters your body, the immune system destroys them
What is the most important part of your immune system and why
White blood cells, they travel around in your blood and crawl into every part of you, constantly patrolling for microbes ready to attack
What are the three lines of attack
- Consuming them
- Producing antibodies
- Producing antitoxins
How would consuming them attack microbes
White blood cells can engulf foreign cells and digest them. This process is called phagocytosis
How would producing antibodies attack microbes
Every invading pathogen has unique molecules called (antigens) on its surface
When some types of white blood cell come across a foreign antigen
they will start to produce proteins called antibodies to lock into the invading cells and destroy them
Antibodies are them produced rapidly and carried around the body
Why do the antibodies produced only target specific pathogens
Because of their antigen
What if the person is infected with the same pathogen again
The white blood cells will rapidly produce the antibodies to kill it- the person is naturally immune to that pathogen
What are the white blood cells called that produce antibodies
B- lymphocytes
How is producing antitoxins going to defend
These counteract toxins produced by the invading bacteria
