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The Respiratory System: What is it?
Breathe in.....breathe out.....you just used your respiratory system.
When you breathe in, your body takes in oxygen. When you breathe out, your body expels carbon dioxide. It is vital for our bodies to continually exchange these two gases, and it is the respiratory system that is doing that job for you. This exchange happens quickly and often — whether we are awake or sleep.
So why do we need oxygen? Once oxygen is in our cells, it burns the fuel which then produces energy. Oxygen-turned-into-energy helps us in many ways: among many other things, it contracts our muscles, repairs our cells, and feeds our brain.
When you breathe out, the waste gases, like carbon dioxide, are expelled from the body. So the respiratory system also acts as a cleansing system, getting rid of toxins that your body doesn't need.
What are the parts of the respiratory system?
The parts of the respiratory system include:
- The Lungs: the primary organ of the respiratory system where the exchange of gases occurs;
- The Trachea or windpipe: a tube which extends from the larynx to the bronchial tubes and moves air to and from the lungs;
- The Bronchial Tubes (including the alveoli): two tubes which move air from the trachea to the lungs;
- The Capillaries: the smallest of blood vessels. which distribute oxygenated blood from arteries to the tissues of the body and feed deoxygenated blood from the tissues back into the veins;
- The Diaphragm: a dome-shaped, muscular partition which separates the lungs from the abdomen and plays a major role in the breathing process (see more in the sidebar below).
The average rate of breathing is dependent upon a person's age:
- A newborn's breathing rate is about 40 times each minute and may slow to 20 to 40 times per minute when sleeping 2.
- For adults, the average resting respiratory rate for adults is 12 to 16 breaths per minute 3. Physical exertion also has an effect on respiratory rate, and healthy adults can average 45 breaths per minute during strenuous exercise.
How does the respiratory system work?
Everyone understands the general principle of how the respiratory system works, but here is a more detailed look at the process.
Here are the stages of the breathing cycle 4 :
Oxygen enters the nose or mouth.
The air then passes through the sinuses which help to regulate the temperature and humidity.
As air goes through the trachea, it is filtered more and enters the bronchi.
The bronchi are lined with tiny hairs called cilia which move back and forth and carry mucus up and out. (Note: Mucus, a sticky fluid, collects dust and that have invaded the lungs. We get rid of it when we sneeze, cough, spit or swallow.)
The bronchial tubes lead to the lobes of the lungs. (The right lung has three lobes; the left lung has two.) Lobes are filled with small, spongy sacs called alveoli. This is where the exchange of oxygen and carbon dioxide occurs.
The alveolar walls are extremely thin and are composed of a single layer of tissues called epithelial cells and tiny blood vessels (pulmonary capillaries).
Blood passes through the capillaries. The pulmonary artery carries blood containing carbon dioxide to the air sacs, where the gas moves from the blood to the air. Oxygenated blood goes to the heart through the pulmonary vein, and the heart pumps it throughout the body.
What are the diseases and disorders of the respiratory system?
Diseases and conditions of the respiratory system include:
- Bacterial Pneumonia: there are several different types;
- Asthma: a chronic inflammation of the lung airways that causes coughing, wheezing, chest tightness or shortness of breath;
- Chronic Obstructive Pulmonary Disease (COPD): the intersection of three conditions — chronic bronchitis, chronic asthma and emphysema; as a progressive disease, it becomes increasingly difficult for sufferers to breathe;
- Lung cancer: caused by the uncontrolled growth of abnormal cells.
Can exercise help the respiratory system?
Since the respiratory system's job is to tranport oxygen and carbon dioxide to and from muscles and tissues, exercise can be greatly beneficial to this system because, during exercise, the respiratory system increases its efforts to meet the demands of the working muscles. At the same time, the cardiovascular system is also increasing its efforts.
There are several ways exercise assists the respiratory and cardiovascular systems:
Increases Cardiac output: During exercise, production of certain hormones increases which affects the heart's ability to transport oxygen and carbon dioxide. These hormones influence the sympathetic nerves to stimulate the heart to beat stronger (stroke volume) and faster (for increased heart rate and cardiac output).
Improves Oxygen Transport: While exercising, additional oxygen must be transported through the blood vessels. The sympathetic nerve stimulates the veins to constrict — which returns more blood to the heart. This blood is carrying carbon dioxide from the muscles and can increase the stroke volume of the heart by 30 to 40 percent.
Raises Respiratory Rate (or rate of breathing): With an increased amount of oxygen and carbon dioxide transport, your respiratory rate — rate of breathing — also increases. At rest, your respiratory rate is about 14 per minute but can increase to 32 per minute during exercise. The increased respiration rate allows more oxygen to reach the lungs and blood to be delivered to the muscles.
Long Term Response Improvements: A long-term respiratory system response to exercise involves several adaptations which ultimately result in an increase in overall efficiency of the respiratory system. This efficiency can be measured through testing, and studies show that through long-term and regular exercise, the respiratory system improves its ability to function.
Cardiovascular exercise (walking, running, dancing, moving) does more to help the respiratory system than any other form of exercise. It is why it is included in every fitness class.
Other articles of interest:
- The Cardiovascular System: The Transportation of Blood through the Body
- Exercise and COPD
- Exercise and Heart Disease
- Good Breathing
I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.