# data[].attributes.body
Regular physical activity in childhood and adolescence is important for promoting lifelong health and well-being and preventing various health conditions.1–2 The 2008 US Physical Activity Guidelines for Americans recommend that children and adolescents  aged 6 to 17 years should have 60 minutes (1 hour) or more of physical activity each

# data[].attributes.headline
The circulatory system is extremely long

# data[].attributes.subject
The circulatory system is extremely long

# data[].attributes.body
-about 2,000 gallons of blood travel through the body.
-an average adult has 5 to 6 quarts of blood.
-heart beats around 3,000,000,000 a person’s life.
-In a tiny drop of blood, there are 5 million blood cells.
- Thousands of blood vessels in your blood.

# data[].attributes.headline
Red blood cells must squeeze through blood vessels.

# data[].attributes.subject
Red blood cells must squeeze through blood vessels.

# data[].attributes.body
Capillaries are tiny, averaging about 8 microns (1/3000 inch) in diameter, or about a tenth of the diameter of a human hair. Red blood cells are about the same size as the capillaries through which they travel, so these cells must move in single-file lines.
Some capillaries, however, are slightly smaller in diameter than blood cells, forcing the cells to distort their shapes to pass through.

# data[].attributes.headline
The circulatory system is extremely long.

# data[].attributes.subject
The circulatory system is extremely long.

# data[].attributes.body
If you were to lay out all of the arteries, capillaries and veins in one adult, end-to-end, they would stretch about 60,000 miles (100,000 kilometers). What's more, the capillaries, which are the smallest of the blood vessels, would make up about 80 percent of this length.
By comparison, the circumference of the Earth is about 25,000 miles (40,000 km). That means a person's blood vessels could wrap around the planet approximately 2.5 times!

# data[].attributes.headline
There is a video 11 Surprising Facts About the Circulatory System

# data[].attributes.subject
There is a video 11 Surprising Facts About the Circulatory System

# data[].attributes.body
https://youtu.be/yMorctYmNUs

# data[].attributes.body
11 Surprising Facts About the Circulatory System.
The circulatory system includes the heart, blood vessels and blood, and is vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance). The system's main function is to transport blood, nutrients, gases and hormones to and from the cells throughout the body.
Here are 11 fun, interesting and perhaps surprising facts about the circulatory system that you may not know.

# data[].attributes.body
What is the circulatory system? the system that circulates blood and lymph through the body, consisting of the heart, blood vessels, blood, lymph, and the lymphatic vessels and glands.