Video Transcript
Fill in the blank. In the pulmonary circulatory
system, the blood being transported from the heart to the lungs is blank. (A) Oxygenated or (B)
deoxygenated.
This question asks us about the
pulmonary circulatory system, which is one component of the double circulatory
system in humans. The other component is called the
systemic circulatory system. Let’s review these two parts of the
circulatory system in more detail and the substances that they can transport.
The entire circulatory system is
composed of the heart and its vessels. Arteries are blood vessels that
carry blood away from the heart. Veins are blood vessels that carry
blood into the heart. The word systemic refers to the
entire body, so the systemic circulatory system is responsible for delivering
oxygenated blood to all of the body cells. While the systemic arteries supply
the body cells with oxygenated blood, the systemic veins return deoxygenated blood
containing carbon dioxide and other waste products of the body cells to the
heart.
When the oxygenated blood arrives
back at the heart, it is pumped to the lungs through pulmonary arteries. You might already know what occurs
here. Carbon dioxide is exchanged for
oxygen in a process called oxygenation. And once oxygenated, blood is
returned to the heart by the pulmonary veins. This oxygenated blood can then
enter the systemic circulatory system again so that it can be pumped from the heart
to the body cells.
Now that we’ve covered the systemic
and pulmonary circuits of the circulatory system, we can answer the question as to
what type of blood is pumped from the heart to the lungs in the pulmonary
circuit. We know now that this blood is
deoxygenated, as the oxygen it once contained will have mostly been absorbed into
and used by the body cells. Therefore, to fill in the blank in
the question, in the pulmonary circulatory system, the blood being transported from
the heart to the lungs is deoxygenated.
