The New Childrens Encyclopedia

(Marvins-Underground-K-12) #1
How many
nerve cells are

in a human brain?


Find out on pages


280–281


How many bones are
in an adult human skeleton?
Find out on
page 274

You blink more than 9,000 times a day.


In most places, your skin is about


1
⁄ 16 in (2 mm) thick.

In a fingernail-sized patch of skin, there can be up to 600 sweat glands.


On average, a human body contains enough iron to make a nail 1 in (2.5 cm) long.


A drop of blood contains around 5 million red blood cells.


Definition: The human


body is an amazing machine.


Humans are mammals who


breathe air and eat plants


and animals to nourish their


bodies and provide energy.


THE HUMAN BODY
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