The Importance of Oxygen in Animals
Oxygen is a vital gas that all animals require to survive and perform daily functions. Animals need oxygen in order to carry out cellular respiration, which turns food into energy. This process occurs in the mitochondria and requires glucose from the food you eat and oxygen from the air you breathe. This combined creates carbon dioxide, which is waste that is breathed out, water and ATP (energy that all living cells need).
When humans inhale, they take in oxygen from the air, which travels into the lungs that have millions of alveoli. The oxygen is absorbed through diffusion into the blood and the blood vessels surrounding the alveoli carry the oxygenated blood the heart. The blood from the heart containing carbon dioxide returns into the alveoli and leaves the lungs.
When humans inhale, they take in oxygen from the air, which travels into the lungs that have millions of alveoli. The oxygen is absorbed through diffusion into the blood and the blood vessels surrounding the alveoli carry the oxygenated blood the heart. The blood from the heart containing carbon dioxide returns into the alveoli and leaves the lungs.
Gas Exchange in Tortoise Beetles
Tortoise beetles, and insects in general, breathe differently from humans because they don't have lungs. If insects don't have lungs, then how do insects breathe? Well, instead of lungs, they have a system of tubes called the tracheal system to perform gas exchange. Air enters through tiny holes, called spiracles, along the insects' bodies that open into tubes (trachea). The insect can open and close spiracles using muscle contractions. The oxygen then travels to the tracheoles, which extend throughout the body.
The tracheoles end within the cells. The ends of the tracheoles contain tracheole liquid. Gases are exchanged where the fluid and gas meet, near the cells. Oxygen moves to muscles and body parts by diffusion. Carbon dioxide goes through the tracheole and is excreted through the spiracles.