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The Respiratory System

by Dr. Mary Williams, R.N. D.C.

The human body is made up of various systems that help it work correctly. Each of these systems contain organs that work together for a purpose. The respiratory system is one of these systems. The goal of the respiratory system is breathing, which occurs involuntarily. That means that a person doesn't need to think about breathing in order for it to happen. This is a very good thing because people breathe as much as 17,000 times a day. If there is a problem with the respiratory system or a person's breathing, it can cause problems like coughing and wheezing. When a person cannot breathe well, it can become a serious medical problem. Learning about the respiratory system is fascinating and a great way to understand the importance of breathing.


Why Do People Need to Breathe?

People need oxygen to play, talk, walk, and do all of the things that they like. In fact, without oxygen, people would die. Every person gets oxygen from breathing. Breathing allows people to pull oxygen into their bodies and into their bloodstream. Once in the bloodstream, it can travel throughout the body. The respiratory system also helps to release energy into the body's cells. This happens because oxygen releases that energy from food or sugar molecules. In addition, breathing also makes it possible for people to do things like talk and laugh. When a person gets sick with a disease like bronchitis, it can make it hard to breathe and they may need medicine to improve their breathing. If a person is unable to breathe and is unconscious, it is important to perform CPR right away until medical help can arrive. CPR will ensure that the person not breathing is able to get the oxygen that they need.

  • Why We Breathe: The About Kids Health website explains why the human body needs to breathe. On this page, there is a button to click that will start the interactive explanation of why we breathe.
  • Why Do We Breathe and Why Do We Need Lungs to Do it? This page answers the question of why people breathe and why the lungs are needed. The answer that is provided is lengthy and easy to understand.
  • The Respiratory System Lesson: View a page that provides a detailed middle-school lesson on the respiratory system here. Kids will find diagrams of the respiratory system, vocabulary words, review questions, and a tab for additional resources.
  • Why Do We Need to Breathe Oxygen? Click on this link for a very simple explanation of why breathing oxygen is necessary for the human body.
  • Lungs: The Breath of Life: National Geographic has an interesting and informational article on the lungs and breathing that can be read by clicking on this link. There is an interactive slide show that explains and shows lung anatomy and function and the effect of asthma without medicine.
  • Study Jams: The Respiratory System: Learn about the respiratory system by clicking on this link that opens the Scholastic Study Jams! page for this particular body system. Once on this page, students and other readers can click on the slide show to learn about the respiratory system, or they can test themselves by clicking on the "test" button.

Parts of the Respiratory System

The various parts of the respiratory system all work together and play a crucial role in bringing in oxygen and getting rid of carbon dioxide. These parts begin from the moment that air enters the airways. The airways are made up of the nose and mouth; the pharynx, or throat; the voice box, or larynx; the windpipe, or trachea; and the bronchial tubes. The largest of these airways is the trachea. The airways are tubes or pipes that carry air into your body and down into your lungs.

The respiratory system is divided into two tracts. One of these tracts is located outside the cavity of the chest. It is called the upper respiratory system. The second tract is inside the cavity of the chest and is known as the lower respiratory system. Most of the airways are located in the upper respiratory tract, with the exception of the trachea and the bronchial tubes. The sinuses are also a part of the upper respiratory tract. The lungs and the diaphragm are located in the lower respiratory system. The lungs and the diaphragm are critical to the function of breathing. In the lungs, there are the vital parts necessary for providing oxygen to the body. The diaphragm is a muscle that sits below the lungs and above the abdomen. The movement that it makes when it expands and then contracts is what makes it possible for air to enter into the lungs.

  • Remember the Structures of the Respiratory System: The organs of the respiratory system are featured in this PDF. Each of the structures and organs are explained and images are included on each of the pages. These structures are divided into the upper and lower respiratory systems.
  • Health Topics: The Respiratory System: This National Heart, Lung, and Blood Institute link opens to the respiratory system page. On this page, students can view an image of the respiratory system and its structures or read about the airways, lungs, and blood vessels that are a part of this system.
  • Respiratory System: Look at a labeled drawing of the upper and lower respiratory tract by clicking on this link.
  • Respiratory System: Lungs: Read about the lungs and other parts of the respiratory system by clicking on this link. The parts on this page also include the trachea, bronchi, and diaphragm. The page also answers what the respiratory system is.
  • Respiratory System: Functions: Open this link and click on one of the two lung functions that are listed on this page. The interactive image demonstrates the functions, and a description of the selected function is also included near the top of the page.

What Happens When People Breathe?

When a person breathes, pulmonary gas exchange occurs. There are two gases that are exchanged: oxygen and carbon dioxide. Oxygen is what a person inhales, or breathes in. Carbon dioxide is what a person releases when they breathe out, or exhale. Carbon dioxide is a gas that is considered a type of waste that the body creates when oxygen releases energy in the cells. When a person breathes in oxygen, they breathe out carbon dioxide in exchange. This happens when oxygen enters the lungs through bronchial tubes. In each lung, the bronchial tube branches out into bronchioles. Each lung has 30,000 bronchioles that are connected to tiny sacs that look like grape clusters, called alveoli. The walls of the alveoli are covered with blood vessels that are called capillaries. The lungs have roughly six hundred million alveoli. The alveoli are where the gas exchange occurs. When a person inhales, oxygen enters the alveoli, where it enters the blood. The carbon dioxide is released into the alveoli from the veins and exits the body when a person exhales.

  • Respiratory System: Oxygen Delivery System: On this page is a very simple explanation of the respiratory system and how it delivers oxygen. Students can also read about the alveoli and carbon dioxide when they click on this link.
  • How Your Lungs Work: Learn about the lungs and how they work by clicking on this link to the Lung Association website. A majority of the article talks about the alveoli, and the page includes drawings of them.
  • Human Body Systems: Respiratory System: There are a number of systems that are reviewed on the linked page, including the respiratory system. Learn how the air travels into the lungs and what happens in the lungs. Students can click on highlighted words for more information about them.
  • Your Body: Respiratory System Video: At this link, there is an educational and fun video about the respiratory system. The animated video talks about breathing and includes questions and answers about breathing.
  • How the Body Uses O2: Click on this PBS link to learn about how the body uses oxygen.