EQ: Why do you need to breathe? How does your body respire?
Humans, like all other animals, need air to stay alive.
Air is a mixture of gases found in Earth's atmosphere. The
main gases in air are nitrogen and oxygen, which make up
approximately 78 percent and 21 percent of the atmosphere,
respectively. The remaining one percent is made up of gases
present in trace amounts.
The respiratory system consists of the lungs and the
various breathing tubes that allow air to reach the lungs. The
respiratory system allows gas exchange. It brings oxygen into
the body and expels carbon dioxide. All animals must undergo
gas exchange to stay alive.
Before air reaches the lungs, it must first be processed.
Even air that seems clean contains dust particles and bacteria.
If the air entering the body is not processed (filtered, cleaned,
warmed, and moistened), it could carry disease-causing
microorganisms and pollutants into the lungs and damage
lung tissues.
SCIENCE CONNECTIONS
The respiratory system ensures
that you have a steady supply of
clean and filtered air that goes
into the lungs in the same way
that particulates are filtered by
a cabin air filter in a car engine.
The adult human body requires
around 90 pounds of oxygen
per day to function normally.
Approximately 20 percent of this
inhaled oxygen goes to the brain.
The blood transports oxygen to the
brain through the internal carotid
arteries and vertebral arteries.
The brain needs a constant flow
of oxygen-rich blood in order to
keep up with the heavy metabolic
demands of the neurons.
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