Immune system and types of immunity

1.      Immune system – The body’s system that protects you from illness and disease.

2.      ​Body – All the physical parts of a person or animal.

3.      ​Protect – To keep someone or something safe from harm.

4.      ​Sickness – The state of being ill; not feeling well.

5.      ​Disease – A serious sickness in the body.

6.      ​Germ – A very small thing, like bacteria or a virus, that can cause sickness.

7.      ​Bacteria – Tiny living things that can cause illness but can also be helpful.

8.      ​Virus – A very tiny germ that can live in your body and make you ill.

9.      ​Skin – The thin layer that covers and protects your body.

10.   ​Blood – The red liquid that moves around your body in veins and carries nutrients.

11.   ​White blood cells – Special cells in the blood that fight germs.

12.   ​Lymph system – A network in the body that helps move infection-fighting cells.

13.   ​Infection – When germs enter the body and start to cause sickness.

14.   ​Antibody – A special protein that helps the body fight a certain germ.

15.   ​Vaccine – A weak or changed germ given to help your body learn to fight a disease.

16.   ​Allergies – Health problems like sneezing or itching because the body reacts to something harmless.

17.   ​Autoimmune disease – When the immune system attacks healthy cells in the body by mistake.

18.   ​Healthy – Being well and strong, without sickness.

19.   ​Stress – A feeling of worry or pressure that can affect your body and mind.

20.   ​Exercise – Physical activity like running or playing sports that helps keep you fit.

21.      Pathogens (bacteria/viruses/fungi): Tiny organisms that can cause illness.

22.      Antigens and antibodies: Antigens are markers on germs that identify them; antibodies are pro-teins made by the body to attack them.

23.      Toxins: Harmful substances produced by some pathogens that can make you feel ill.

24.      Mucus: A sticky substance that traps dust and germs in your nose, throat, and lungs.

25.      Natural barriers: The body’s first line of defence, like skin and stomach acid, that help stop germs from getting in.

      26.   Leukocytes are white blood cells. They help the body fight germs and keep us healthy.

      27. Lymphocytes are a type of white blood cell. They help the body recognize and fight specific   

            germs.

      28. Phagocytes are cells that eat germs. They catch and destroy bacteria and viruses.

The Adaptive Immune System

The adaptive immune system is the part of the body that learns to fight germs.

It recognizes specific germs like viruses and bacteria.

It remembers these germs.

The first time it meets a germ, it works slowly.

The next time, it works faster.

Important cells

B cells: make antibodies to fight germs.

T cells: help the body kill infected cells.

Example

When you get a vaccine, your body learns about a germ.

Later, if the germ enters your body, you do not get very sick.

The adaptive immune system learns, remembers, and protects the body.

The Innate Immune System

The innate immune system is the body’s first protection against germs.

It works fast.

It is not specific (it fights all germs in the same way).

Main parts

Skin: stops germs from entering the body.

Mucus and tears: trap and wash away germs.

White blood cells: attack germs quickly.

Fever: helps kill germs.

Example

When a germ enters your body, the innate immune system acts immediately to protect you.

The innate immune system is fast, simple, and always ready.

Answer the following questions:

1.     What protects your body from germs?

The immune system.

2.      Are viruses and bacteria good or bad for the body?

They can cause disease

3.      What is the first line of defense in your body?

Innate immunity.

4.      Do you have innate immunity when you are born?

Yes, you are born with it.

5.      What kind of immunity learns from experience?

Adaptive immunity

6.      Which system is fast: innate or adaptive?

Innate is fast.

7.      Which system is specific and special?

Adaptive immunity.

8.      What are white blood cells called?

Leukocytes.

9.      Do B cells belong to innate or adaptive immunity?

Adaptive immunity.

10.   T cells are part of which immune system?

Adaptive immunity

11.   True or false: Skin helps stop germs.

True

12.   What is something that helps your body remember a pathogen?

Memory cells

13.   Do antibodies fight specific germs?

Yes, they are specific.

14.   Which immunity acts first when a germ enters?

Innate immunity

15.   What do B cells make to fight germs?

Antibodies.