# data[].attributes.headline
healthy exercise habits for good health!

# data[].attributes.subject
healthy exercise habits for good health!

# data[].attributes.attachment_link.title
Make Healthy Normal - Tips to improve exercise habits

# data[].attributes.body
If you sleep,you don't just get healthy by magic! You should get enough sleep to improve your immune system because if you don't,

# data[].attributes.attachment_link.description
Detailed information on the immune system, including a full-color, labeled illustration of the immune system

# data[].attributes.body
exercise and immunity

# data[].attributes.attachment_link.title
Exercise and immunity: MedlinePlus Medical Encyclopedia

# data[].attributes.attachment_link.description
Battling another cough or cold? Feeling tired all the time? You may feel better if you take a daily walk or follow a simple exercise routine a few times a week.

# data[].attributes.body
kids-health

# data[].attributes.attachment_link.readable_text
What Is the Immune System?

The immune system is the body's defense against infections. The immune (ih-MYOON) system attacks germs and helps keep us healthy.

What Are the Parts of the Immune System?

Many cells and organs work together to protect the body. White blood cells, also called leukocytes (LOO-kuh-sytes), play an important role in the immune system.

Some types of white blood cells, called phagocytes (FAH-guh-sytes), chew up invading organisms. Others, called lymphocytes (LIM-fuh-sytes), help the body remember the invaders and destroy them.

One type of phagocyte is the neutrophil (NOO-truh-fil), which fights bacteria. When someone might have bacterial infection, doctors can order a blood test to see if it caused the body to have lots of neutrophils. Other types of phagocytes do their own jobs to make sure that the body responds to invaders.

The two kinds of lymphocytes are B lymphocytes and T lymphocytes. Lymphocytes start out in the bone marrow and either stay there and mature into B cells, or go to the thymus gland to mature into T cells. B lymphocytes are like the body's military intelligence system - they find their targets and send defenses to lock onto them. T cells are like the soldiers - they destroy the invaders that the intelligence system finds.

How Does the Immune System Work?

When the body senses foreign substances (called antigens), the immune system works to recognize the antigens and get rid of them.

B lymphocytes are triggered to make antibodies. These specialized proteins lock onto specific antigens. The antibodies stay in a person's body. That way, if the immune system encounters that antigen again, the antibodies are ready to do their job. That's why someone who gets sick with a disease, like chickenpox, usually won't get sick from it again.

This is also how immunizations (vaccines) prevent some diseases. An immunization introduces the body to an antigen in a way that doesn't make someone sick. But it does let the body make antibodies that will protect the person from future attack by the germ.

Although antibodies can recognize an antigen and lock onto it, they can't destroy it without help. That's the job of the T cells. They destroy antigens tagged by antibodies or cells that are infected or somehow changed. (Some T cells are actually called "killer cells.") T cells also help signal other cells (like phagocytes) to do their jobs.

Antibodies also can:

neutralize toxins (poisonous or damaging substances) produced by different organisms

activate a group of proteins called complement that are part of the immune system. Complement helps kill bacteria, viruses, or infected cells.

These specialized cells and parts of the immune system offer the body protection against disease. This protection is called immunity.

Humans have three types of immunity - innate, adaptive, and passive:

Innate immunity: Everyone is born with innate (or natural) immunity, a type of general protection. For example, the skin acts as a barrier to block germs from entering the body. And the immune system recognizes when certain invaders are foreign and could be dangerous.

Adaptive immunity: Adaptive (or active) immunity develops throughout our lives. We develop adaptive immunity when we're exposed to diseases or when we're immunized against them with vaccines.

Passive immunity: Passive immunity is "borrowed" from another source and it lasts for a short time. For example, antibodies in a mother's breast milk give a baby temporary immunity to diseases the mother has been exposed to.

The immune system takes a while to develop and needs help from vaccines. By getting all your child's recommended vaccines on time, you can help keep your child as healthy as possible.

# data[].attributes.attachment_link.description
The immune system is the body's defense against infections. The immune (ih-MYOON) system attacks germs and helps keep us healthy. Many cells and organs work together to protect the body. White blood cells, also called leukocytes (LOO-kuh-sytes), play an important role in the immune system.

# data[].attributes.attachment_link.title
Immune System, Part 3: Crash Course Anatomy & Physiology #47

# data[].attributes.attachment_link.title
The Immune System Explained I – Bacteria Infection

# data[].attributes.body
TED-ED Immune system

# data[].attributes.attachment_link.title
How does your immune system work? - Emma Bryce

# data[].attributes.body
https://www.youtube.com/watch?v=24IYt5Z3eC4&t=22s

# data[].attributes.body
another video

# data[].attributes.attachment_link.title
Immune System, Part 2: Crash Course Anatomy & Physiology #46

# data[].attributes.body
This is a video about the jobs of the immune system

# data[].attributes.attachment_link.title
Immune System, part 1: Crash Course A&P #45