fighting diseases - immune system and defences

What prevents pathogens from getting into the body and what destroys pathogens inside body

Physical and chemical barriers stop pathogens from getting into the body and the immune system destroys the pathogens in the body

What are some physical and chemical barriers

– The skin acts as a barrier to pathogens. It also secretes antimicrobial substances which kill pathogens.

– Hairs and mucus in your nose trap particles that could contain pathogens.

– The trachea and bronchi secrete mucus to trap pathogens.

– The trachea and bronchi are lined with cilia. These are hair like structures, which waft the mucus up to the back of the throat where it can be swallowed.

– The stomach produces hydrochloric acid. This kills pathogens that make it make it that far from the mouth.

What happens if pathogens make it into the body

What’s the most important part of ____ and what does it do

Your immune system kicks in to destroy them. The most important part of the immune system is the white blood cells. They travel around in your body and crawl into every part of you constantly patrolling for microbes when they come across an invader microbe they have three lines of attack, consuming them producing antibodies and producing antitoxins.

What happens in immune system what does white blood cells do

Consume them – white blood cells can evolve foreign cells and digest them. This is called phagocytosis

Producing anti toxins – these counteract toxins produced by the invading bacteria

Producing antibodies – when your white blood cell comes across a foreign antigen, they will start to produce proteins called antibodies to lock onto the invading cells so that they can be found and destroyed by other white blood cells

What is the difference between antigens and antibodies

Antigens – substances that are immune system detects as being foreign.

Antibodies – small proteins made by white blood cells that can lock onto foreign antigens and act as signal to other white blood cells to destroy them

Why can’t antibodies lock onto other antigens

The antibodies produced a specific to that type of antigen so they won’t look onto any others.

What happens after antibodies lock onto antigens and what happens if the person is infected with the same pathogen again

After antibodies lock onto antigen. Antibodies are then produced rapidly and carried around the body to find all similar bacteria or viruses.

– 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 and won’t get ill.