You are wonderfully made: your lungs

The Earth’s atmosphere contains all of the elements we need to breathe and survive on this planet. Your lungs are the vital organs of your respiratory system, which moves about 12,000 quarts of air a day into and out of your lungs. Over 99% of the air we breathe is composed of nitrogen, oxygen, argon and carbon dioxide, in order of volume. The rest of the atmosphere contains trace amounts of gases like neon and krypton.  Although nitrogen is the predominant gas, it doesn’t interact with anything in the body, but is an important support gas that keep the lungs open with its constant presence.
Every one of the trillions of cells that make up all of your body parts need oxygen in order to produce energy. The primary purpose of the respiratory system is to transport oxygen from the atmosphere into the bloodstream where it travels into your cells, and then to remove the waste gas, carbon dioxide, which is produced during cell metabolism. The process by which oxygen is exchanged for carbon dioxide is called respiration. When this takes place in the lungs, it’s called external respiration; when it takes place in your cells, it’s called internal respiration.
One of the wonders of creation is that the respiration process in plants is exactly opposite that of humans and other animal species. Plants take in carbon dioxide and use it to produce energy, then release oxygen into our atmosphere. Humans take in oxygen and use it to produce energy, and release carbon dioxide into our atmosphere. So, you can see the interdependent nature of plants and animals, and a functional design in the creation of life on Earth. Plants and animals have been designed to assist each other in staying alive.
Since your body doesn’t have any way to store oxygen, and the reserve lasts only four to six minutes, it must continually be replenished by your breathing. From the time you take your first breath, your respiration takes place without you thinking about it, by the automatic processes of your nervous system and your brain.
To become more aware of the cycle of life flowing through you, focus on your breathing. Think about life-giving oxygen streaming into your body, moment to moment, fueling your cells and giving you strength. Think about the steady rhythm of your breathing, calming your emotions and providing a sense of peace. Take a deep breath; feel the vitality in the air. Treasure every breath. It is the breath of life. Your wonderful life.
Now ponder this: Because you breathe, you live. Because you live, you contribute something unique to this world that didn’t exist before you were born.