Download How Does Your Body Take In Oxygen?

Lesson 1
How Does Your
Body Take In
Oxygen?
Respiratory System
• When you breathe in your respiratory
system brings air containing oxygen into
your body.
• The respiratory system includes the nose,
nasal cavity, pharynx, larynx, trachea,
bronchial tubes, lungs, and alveoli.
• As your cells work, they make a gas called
carbon dioxide. This gas leaves your body
when you breathe out.
Nose
• The nose has the job of getting air ready
for your lungs.
• The lining of your nose produces a thick,
sticky liquid called mucus.
• Tiny hairs in your nasal passages, bronchi,
and trachea called cilia help to clean the
air of dust and dirt particles.
Inside Your Lungs
• The process of breathing in is called
inhaling.
• The exchange of oxygen for carbon
dioxide in the lungs takes place in air sacs
called alveoli.
• The process of breathing out is called
exhaling.
Lesson 2
How Does Your
Body Use
Oxygen?
Capillaries
• Capillaries are tiny blood vessels with very
thin walls through which oxygen and
nutrients can pass.
• As red blood cells move through a
capillary, they release their oxygen to body
cells outside of the capillary.
Red Blood Cells
• When red blood cells are carrying oxygen,
they are bright red.
• After red blood cells give up their oxygen,
they become dark, dull, and purplish.
Using Oxygen to Release
Energy
• Nutrients are carried by plasma to the
body cells.
• Many nutrients are simple kinds of sugar.
• Cells use oxygen to break the sugar down
into carbon dioxide and water. This
releases energy.
Sugar + Oxygen
energy
carbon dioxide + water +
Energy
• The body needs more energy when you
are very active, so more oxygen is needed
by the cells.
• You can get more oxygen with each breath
when you breathe faster and when you
breathe through your mouth.