Asked in Human Anatomy and Physiology
Human Anatomy and Physiology
How much energy does the brain require?
Answer

Wiki User
June 13, 2012 2:28AM
The brain consumes about 25 % of the body's energy when at rest.
So for a typical person, on an average day, this equates roughly to 24 watts (based on 2,500 Calories/day).
But the energy usage of the brain does vary depending on the level of mental exertion. Studies have shown that when performing difficult mental activities, the energy usage of the brain increases.
See the following link for more background:http://www.physicsforums.com/showthread.php?t=42053
Related Questions
Asked in Integumentary System (skin)
How many mitochondria does a skin cell have?

Cells that require the most energy contain the most energy
generating mitochondria. The cells of the brain, the skeletal
muscle and heart muscle, and the eye contain the highest number of
mitochondria (as many as 10,000 per cell) while the skin cells,
which do not require much energy, contain only a few hundred of
them.
Asked in Health, Dieting and Weight Loss, Nutrition, Ancient Greece
If you do not eat breakfast will your brain still work the same way as when you eat breakfast?

Not necessarily. Your brain is an extremely needy organ. The
cells in your brain require about 2 times as much energy as that of
other cells in your body. Without the fuel that breakfast provides
for your brain, you won't be as productive until you eat something.
Complex carbohydrates like fruits and vegetables can keep you full
for quite a while and provide your brain with the energy it needs
to operate as well as it can. Simpler carbohydrates such as sugar
also provide energy but not for as long as complex ones do.
Asked in Human Anatomy and Physiology
Why does the brain require such a large percentage of the body's total blood flow?

The brain contains billions of neurons (nerve cells) which are
constantly sending signals to each other and to the rest of the
body, whether you're awake or asleep. The neurons send their
signals by pumping ions into and out of themselves, which takes
energy. Each neuron has millions or billions of ion pumps, so even
though a single ion pump doesn't use much energy, all the ion pumps
in a neuron multiplied over the billions of neurons in the brain
require substantial energy to operate. The blood that travels to
the brain delivers the oxygen and glucose necessary for the brain
to maintain these activities.