Monday
Monday: Why Am I Out of Breath?
Rocket bursts through the kitchen door after racing Raven to the corner and back. He flops against the Windowsill, puffing.
"I am breathing so fast," he gasps. "And my heart is thumping. Two things at once."
Raven is breathing hard too, but she is already counting. "What do you notice? Both numbers went up together."
"Last week we counted the heart," Rocket says. "This week the lungs?"
Nova hovers between them, her light pulsing slowly. "What do your legs need more of when they run?" she asks.
"Air," Rocket says. Then he stops. "No. Something in the air."
Raven writes a new heading in the Log: lungs, heart, muscles. One job.
The body is a system of systems
Last week you climbed the ladder from cell to organism. This week you look at how the organ systems work together.
The body is a system of interacting subsystems. Each subsystem is made of groups of cells, formed into tissues and organs.
No system works alone. The lungs, the heart and the muscles each do a job, and the jobs fit together.
What the lungs do
The lungs have two main functions. One is to get oxygen from the air into the body. The other is to remove carbon dioxide.
Your body needs oxygen to work properly. Carbon dioxide is a gas your body produces when it uses oxygen.
When you breathe in, air flows through the airways into the lungs. It keeps flowing until it fills tiny air sacs called alveoli.
Oxygen crosses into the body where the vessels and the air sacs meet. Carbon dioxide crosses the other way, to be breathed out.
What the circulatory system does
The circulatory system is a network of vessels and a pump, the heart. It reaches all parts of the body.
This network supplies the cells, tissues and organs with oxygen and nutrients. It removes carbon dioxide and waste.
In the lungs, oxygen is picked up and carbon dioxide is released. So the circulatory and respiratory systems work in tandem.
That is why Rocket felt two things at once. One system was filling with oxygen, and the other was delivering it.
- Read the question.
- Tap your answer.
| Statement | True or false? |
|---|---|
| The lungs have two main functions: bring in oxygen and remove carbon dioxide. | ? |
| The circulatory system and the respiratory system work separately. | ? |
| Oxygen crosses into the body where vessels meet the air sacs. | ? |
| The body produces carbon dioxide when it uses oxygen. | ? |
Count each breath. One in and one out is one breath. Write the number in your Windowsill Log.
Keep it. You will compare it with your lab numbers on Wednesday.
Breath and pulse counts here are like measuring a seedling. They are not a health check and carry no medical advice.
The facts come from the MedlinePlus medical encyclopedia and the OpenStax textbook Concepts of Biology, both free online.
Good start. Tomorrow you will trace a breath from your nose to the alveoli and follow the oxygen onward.