Body & Senses
How does our body defend itself against germs?
Invisible intruders and many helpers: the Wusels explore the body's defences.
The short answer
Skin and moist body linings help keep germs out. If germs get inside, special cells can recognise and fight them. This protection is called the immune response. It does not always succeed: being ill is not a personal failure.
An imagined Wusel scene
Puschel and Flauschi investigate
Puschel and Flauschi first look only for immune cells in a picture. Then Flauschi points to the skin at its edge. Puschel adds it to his drawing as an outer protective layer.
His picture now shows two things: protection outside and help inside.
Try explaining it
What belongs to the body's first protective barrier?
Choose a), b) or c), then explain your choice.
- a)The skin.
- b)The bones inside the body.
- c)The heart pumping inside the body.
Show the explanation
Correct: a): The skin.
Skin and moist body linings help keep germs out. If germs get inside, special cells can recognise and fight them. This protection is called the immune response. It does not always succeed: being ill is not a personal failure.
Word help
- cell
- A tiny living unit. Living things are made of cells.
- membrane
- A thin layer or surface. In a speaker, it vibrates and moves air.
- immune system
- The body's cooperating protective parts that defend against germs.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
Understand step by step
How it works – simply explained
A first boundary protects
Skin and mucous membranes make entry harder for germs. Mucous membranes are moist inner surfaces, such as inside the nose. Protection does not mean nothing ever gets through.
Helpers work inside
Different immune cells recognise and combat intruders. These cells and other body parts form the immune system, a cooperating defence, not one tiny guard.
Extra protection helps
Handwashing and recommended vaccinations support protection. Vaccines prepare defences for particular germs. Someone can still become ill; this does not mean they did something wrong.
Preparing protection is different from curing illness
Recommended vaccines help the immune system recognise particular germs or parts of them and build protection. Germs include some viruses and bacteria that can cause illness. This is preparation, not protection against every disease or a replacement for care when ill. Adults discuss suitable vaccines with professionals.
References for this explanation: [1]
Additional specialist reference: CDC: Grundlagen der Impfung
The key points again
Discovery 1
Skin and mucous membranes are important first barriers.
Source: [1]
Discovery 2
The immune system includes cells and organs that can recognise and fight disease-causing germs.
Source: [1]
Discovery 3
Defences are not perfect. Hygiene and recommended vaccines support protection; illness is not a personal failure.
Source: [1]