1. Weight . The weight of the human brain is
about 3 lbs.
2. Cerebrum . The cerebrum is the largest part of
the brain and makes up 85% of the brain’s
weight.
3. Skin. Your skin weighs twice as much as your
brain.
4. Gray matter. The brain’s gray matter is made
up of neurons, which gather and transmit
signals.
5. White matter . The white matter is made up of
dendrites and axons, which create the network
by which neurons send their signals.
6. Gray and white . Your brain is 60% white
matter and 40% gray matter.
7. Water . The brain is made up of about 75%
water.
8. Neurons . Your brain consists of about 100
billion neurons.
9. Synapses . There are anywhere from 1,000 to
10,000 synapses for each neuron.
10. No pain . There are no pain receptors in the
brain, so the brain can feel no pain.
11. Largest brain . While an elephant’s brain is
physically larger than a human brain, the
human brain is 2% of total body weight
(compared to 0.15% of an elephant’s brain ),
meaning humans have the largest brain to
body size.
12. Blood vessels . There are 100,000 miles of
blood vessels in the brain.
13. Fat . The human brain is the fattest organ in
the body and may consists of at least 60% fat .
The Developing Brain
Starting from within the womb, fetal brain
development begins the amazing journey that leads
to a well-developed brain at birth that continues to
grow for 18 more years.
14. Neurons . Neurons develop at the rate of
250,000 neurons per minute during early
pregnancy.
15. Size at birth . At birth, your brain was almost
the same size as an adult brain and contained
most of the brain cells for your whole life.
16. Newborn’s growth . A newborn baby’s brain
grows about three times its size in the first
year.
17. Stopped growing. Your brain stopped growing
at age 18.
18. Cerebral cortex . The cerebral cortex grows
thicker as you learn to use it.
19. Stimulation . A stimulating environment for a
child can make the difference between a 25%
greater ability to learn or 25% less in an
environment with little stimulation.
20. New neurons . Humans continue to make new
neurons throughout life in response to mental
activity.
21. Read aloud. Reading aloud and talking often to
a young child promotes brain development.
22. Emotions . The capacity for such emotions as
joy, happiness, fear, and shyness are already
developed at birth. The specific type of
nurturing a child receives shapes how these
emotions are developed.
23. First sense . The first sense to develop while
in utero is the sense of touch. The lips and
cheeks can experience touch at about 8 weeks
and the rest of the body around 12 weeks.
24. Bilingual brains . Children who learn two
languages before the age of five alters the
brain structure and adults have a much denser
gray matter.
25. Child abuse and the brain . Studies have shown
that child abuse can inhibit development of
the brain and can permanently affect brain
development.
Brain Function
From the invisible workings of the brain to more
visible responses such as yawns or intelligence, find
out how the brain functions with these facts.
26. Oxygen . Your brain uses 20% of the total
oxygen in your body.
27. Blood . As with oxygen, your brain uses 20%
of the blood circulating in your body.
28. Unconsciousness . If your brain loses blood
for 8 to 10 seconds, you will lose
consciousness.
29. Speed . Information can be processed as slowly
as 0.5 meters/sec or as fast as 120 meters/
sec (about 268 miles/hr).
30. Wattage . While awake, your brain generates
between 10 and 23 watts of power–or enough
energy to power a light bulb.
