Read more: Curious Kids: when I swipe a matchstick how does it make fire? Breathing pure oxygen sets off a series of runaway chemical reactions. Oxygen radicals harm the fats, protein and DNA in your body. But breathing pure oxygen can sometimes be necessary.
Astronauts and deep-sea scuba divers sometimes breathe pure oxygen because they work in very dangerous places. Sick people, including premature babies in hospital or people in hospital with the coronavirus , might also need some extra help breathing. It acts like a medicine to help calm and settle their breathing.
The energy released is stored in a chemical compound called adenosine triphosphate ATP , which contains three phosphate groups. When we need energy to carry out an activity, ATP is broken down into adenosine diphosphate ADP , containing only two phosphate groups. Breaking the chemical bond between the third phosphate group and ATP releases a high amount of energy.
Our lungs supply oxygen from the outside air to the cells via the blood and cardiovascular system to enable us to obtain energy. As we breathe in, oxygen enters the lungs and diffuses into the blood. It is taken to the heart and pumped into the cells. At the same time, the carbon dioxide waste from the breakdown of sugars in the cells of the body diffuses into the blood and then diffuses from the blood into the lungs and is expelled as we breathe out.
One gas oxygen is exchanged for another carbon dioxide. This exchange of gases takes places both in the lungs external respiration and in the cells internal respiration. Fig 1 summarises gas exchange in humans. Our respiratory system comprises a conduction zone and a respiratory zone. The conduction zone brings air from the external environment to the lungs via a series of tubes through which the air travels.
These are the:. The nasal cavity has a large number of tiny capillaries that bring warm blood to the cold nose. The warmth from the blood diffuses into the cold air entering the nose and warms it. The lining of the pharynx and larynx which form the upper respiratory tract and the lining of the trachea lower respiratory tract have small cells with little hairs or cilia.
These hairs trap small airborne particles, such as dust, and prevent them from reaching the lungs. The lining of the nasal cavity, upper respiratory tract and lower respiratory tract contains goblet cells that secrete mucus. It also traps particles, which the cilia then sweep upwards and away from the lungs so they are swallowed into the stomach for digestion, rather than getting trapped in the lungs.
This mechanism of moving trapped particles in this way is known as the mucociliary escalator. The lungs are a little like balloons: they do not inflate by themselves, but only do so if air is blown into them. We can blow into the lungs and inflate them — which is one of the two techniques used for cardiopulmonary resuscitation — but that does not happen in the normal daily life of healthy people.
We have to inhale and exhale air by ourselves. How do we do that? We have two lungs right and left contained in the thoracic cavity chest. Surrounding the lungs are ribs, which not only protect them from damage but also serve as anchors for the intercostal muscles.
Beneath the lungs is a very large dome-shaped muscle, the diaphragm. All these muscles are attached to the lungs by the parietal and visceral membranes also called parietal and visceral pleura. The parietal membrane is attached to the muscles and the visceral membrane is attached to the lungs. The liquid between these two membranes, pleural fluid, sticks them together just as panes of glass become stuck together when wet.
As the visceral membrane covers, and is part of, the lungs and is stuck by pleural fluid to the parietal membrane, when the muscles in the thorax move, the lungs move with them. If air gets between the membranes, they become unstuck and, although the muscles can still contract and relax, they are no longer attached to the lung — as a result, the lung collapses.
This abnormal collection of air in the pleural space is called a pneumothorax. If the pleural fluid liquid becomes infected, the person develops pleurisy. When the intercostal muscles contract, they move up and away from the thoracic cavity. When the diaphragm contracts, it moves down towards the abdomen. This movement of the muscles causes the lungs to expand and fill with air, like a bellows inhalation. Conversely, when the muscles relax, the thoracic cavity gets smaller, the volume of the lungs decreases, and air is expelled exhalation.
When the thoracic muscles contract, the volume of the lungs expands so there is suddenly less pressure inside them. Oxygen plays a critical role in respiration, the energy-producing chemistry that drives the metabolisms of most living things.
We humans, along with many other creatures, need oxygen in the air we breathe to stay alive. Oxygen is generated during photosynthesis by plants and many types of microbes.
Plants both use oxygen during respiration and produce it via photosynthesis. Also ask students what happens to the glass or anything else that comes near the flame it gets hot because of the release of heat energy.
Now ask students to think of food again as the source of energy. Help them to establish a relationship. Begin by pointing out that fire is only one form of oxidation! Oxidation also occurs in your body: When the carbohydrates and fats in your body combine with the oxygen you inhale, they produce carbon dioxide CO 2 and release energy, oxidization.
Students should discuss the relationship in terms of oxidation. After students have read the information on the websites, review the information with them. You can use the text in the second part of teacher sheet to help.
Give students approximately 10 minutes to write a two-paragraph summary of what they learned from this lesson. Ask for some volunteers to read what they learned. More specifically, we depend on oxygen to breathe. Without it, we would die. However, with it, we thrive. Enough oxygen must reach the tiny cells throughout our body to feed them, giving them the energy necessary for life. A fit body can absorb more oxygen. A body that is not overweight also needs less oxygen.
Fitness combined with a healthy and balanced diet is the true secret of having a healthy life!
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