GLOSSARY
alveoli:
Tiny air sacs in the lungs.
aorta:
The biggest artery
in the body.
arteries:
Tubes that carry blood
away from the heart.
blood:
The red fluid that circulates
in the heart, arteries, capillaries,
and veins of a vertebrate animal;
it brings nourishment and oxygen
to and carries away waste products
from all parts of the body.
blood vessels:
Tubes that carry
blood throughout the body; they
are arteries, capillaries, and veins.
capillaries:
Small tubes that carry
blood in the body.
carbon dioxide:
A colorless,
odorless gas that is a byproduct
of animal respiration.
circulatory system:
The body
system that controls blood flow.
nutrients:
Substances your body
needs to stay healthy and to grow.
organ:
A part of the body
that does a certain job.
oxygen:
A gas found in the
air, which people need to live.
pulse:
A regular, rhythmic
throbbing caused by the
squeezing and relaxing
of the heart.
valves:
Moving parts that
control the flow of liquid,
such as blood.
veins:
Tubes that carry
blood to the heart.
