Respiration Lesson

Bronchi and lungs of man Image How can the act of breathing bring materials the body needs to its cells and take away waste products? What is the path that our breath takes as it delivers necessary resources to our body? Respiration begins when air enters your body through the nose or mouth. Next, air will travel down the back of your throat or pharynx. Then the air will move from the pharynx to the trachea. A person will choke if food enters the trachea. That is why the epiglottis is so important. It is a small flap of connective tissue at the base of the tongue that folds text annotation indicator over the trachea when you swallow. The bottom of the trachea is divided into two passageways. Each passageway, or bronchus, leads into the lungs. The bronchus continues to divide into tree-like branches inside the lungs. At the tip of these structures are tiny sacs of lung tissue known as alveoli. The alveoli are surrounded by a cluster of blood vessels called capillaries. This is where gas exchange occurs in the body. The capillaries help the inhaled air get absorbed into the blood. This oxygenated blood will leave the lungs and travel to the heart. While oxygen is moving into the blood, carbon dioxide is moving into the alveoli. Your blood carries carbon dioxide from the capillaries to the lungs. Carbon dioxide is released from our lungs when we breathe out. Therefore we exhale to remove carbon dioxide from our body. The respiratory system is a group of organs that help you breathe by taking in oxygen and giving off carbon dioxide.

How does breathing occur? The presentation below discusses this and other topics.

The air we breathe in contains several different gases but the one we need to survive is of course oxygen. About 21% of our atmosphere is made up of oxygen. The cells in your body need oxygen to help convert glucose from food into energy. Cells need this energy to carry out metabolic functions and activities. The circulatory system is responsible for carrying blood with both glucose and oxygen to the cells of your body. Therefore the respiratory, circulatory, and digestive systems work together to provide your body with energy.

Most organisms have evolved to live in an environment that has a very specific set of conditions. Those creatures that breathe air, for example, have come to rely on that air containing about 21 percent oxygen. If this percentage were to change suddenly, most organisms would have difficulty coping with the new conditions--humans included!

Watch the following presentation to learn more about how our lungs work.

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