Respiration is so automatic that we rarely think about it, unless we feel that enough air is not getting into our bodies. Read through this article to learn about the respiration process.
Have you ever felt out of breath? It isn’t a comfortable feeling. That’s because all the parts of your body need the oxygen gas that you take in with the air that you breathe. When you breathe in, your respiratory system brings the oxygen into your body so that blood can deliver the oxygen to your cells. When you breathe out, you expel a gas called carbon dioxide.
The respiratory system consists of four main parts. The first part is made up of the nose and mouth, through which air enters your body. The inside of your nose is called the nasal cavity. A mucous membrane lines your nasal cavity and it helps keep your nose moist. Little hairs inside your nasal cavity help filter the air you breathe in, and block dirt and dust from getting into your lungs. When you breathe in through your mouth, or oral cavity, the air is moistened, but not filtered.
The nasal cavity and the mouth meet at the pharynx, or throat, at the back of the nose and mouth. From there, air quickly enters the second part of your respiratory system, the trachea or windpipe. The trachea is a tube that delivers air to the lungs, the third and most important part of your respiratory system. In the lungs, the oxygen is absorbed by the blood, which brings it to the rest of the body. The last part of the system is the diaphragm, a layer of muscle that makes up the floor of your rib cage.
When you take a deep breath, your diaphragm contracts. This makes more space in your chest cavity. Air, which contains oxygen, flows through the trachea into large tubes in your lungs called bronchi, causing them to expand. When you let out a deep breath, your diaphragm expands and compresses your lungs, forcing air up into your trachea and out your nose and mouth.
From bronchi, air travels into smaller, branching tubes called bronchioles. The major branches of this system are covered by cilia and a thin film of mucus. The mucus traps dust, pollen, and other contaminants, and the beating cilia move the mucus upward to the pharynx, where it can be swallowed into the esophagus. This process helps to clean your respiratory system.
The bronchioles move the air into tiny air sacs called alveoli. As the air travels from the bronchioles into the alveoli, the tubes get smaller and smaller. When the air reaches the alveoli, the oxygen is separated from the rest of the air and then moved to the tiny blood vessels called capillaries that surround the alveoli. Oxygen is then carried by hemoglobin in the red blood cells to the rest of your body as oxygenated blood rushes from the capillaries in the lungs through larger and larger blood vessels until it returns to the left side of the heart and is pumped throughout the body.
Moving through blood vessels, now called veins, the hemoglobin returns carbon dioxide through the heart and to the lungs. Carbon dioxide is released back out as you exhale, and the process starts all over again.