THE NATIONAL ANTHEM

PLEDGE

PREFACE

RESPIRATORY SYSTEM

CONTENT

RESPIRATORY SYSTEM AND ITS PARTS

VITAL CAPACITY

Did you know that the maximum amount of air your lungs can hold? Your total lung capacity is about 6 liters? That is about three large bottles. Your lungs mature by the time you are about 2025 years old. After about the age of 35, it is normal for your lung function to decline gradually as you age. This can make breathing slightly more difficult as you get older. If you notice any sudden difficulties in breathing or shortness of breath, talk to you doctor right away. This could be a sign of lung disease and not the normal process of aging. A decrease in lung function is a normal part of the aging process but there are steps you can take to stay as healthy as possible. Staying active, avoiding tobacco smoke and stay up to date on vaccinations are just a few ways you can protect and even strengthen your lungs. Apart from protecting the lungs, care should be taken to increase its capacity too. Tidal volume is the volume of air we breathe in and out during normal breathing. In humans, the tidal volume is about 500 ml. Vital capacity is the volume of air that can be breathed out by forceful expiration after maximum or forceful inspiration. Vital capacity can be taken as an indicator of normal and healthy respiratory activity and the strength of muscles in the thoracic cavity. This is about 4.5 litres in male and about 3 litres in female.

Let's measure vital capacity Arrange the plastic jars and tubes as shown in figure 4.3. After a forceful inspiration, blow air forcefully into the first jar holding the funnel aroundthe mouth. Measure the amountof water that falls into the second jar. The volume of water will be proportional to the vitalcapacity. Compare the vital capacity of friends in yourclassroom. Vital capacity can be increased through breathing exercise.

Measurement of vital capacity

RESPIRATORY MOVEMENTS Breathing is a process that take place without our knowledge, during which air is taken in and expelled. The two lungs are the primary organs of the respiratory system. They sit to the left and right of the heart, within a space called the thoracic cavity. The cavity is protected by the rib cage. A sheet of muscle called the diaphragm serves other parts of the respiratory system, such as the trachea, or windpipe, and bronchi, conduct air to the lungs. While the pleural membranes, and the pleural fluid, allow the lungs to move smoothly within the cavity. The process of breathing, or respiration, is divided into two distinct phases. The first phase is called inspiration, or inhaling. When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.

The second phase is called expiration, or exhaling. When the lungs exhale, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs contract and air is forced out.

INSPIRATION

Vital Capacity

Apart from protecting the lungs, care should be taken to increase its capacity too.

Tidal volume is the volume of air we breathe in and out during normal breathing. In humans, the tidal volume is about 500 ml. Vital capacity is the volume of air that can be breathed out by forceful expiration after maximum or forceful inspiration. Vital capacity can be taken as an indicator of normal and healthy respiratory activity and the strength of muscles in the thoracic cavity. This is about 4.5 litres in male and about 3 litres in female.

Let's measure vital capacity

Arrange the plastic jars and tubes as shown in figure 4.3. After a forceful inspiration, blow air forcefully into the first jar holding the funnel around the mouth. Measure the amount of water that falls into the second jar. The volume of water will be proportional to the vital capacity. Compare the vital capacity of friends in your classroom. Vital capacity can be increased through breathing exercise.

Measurement of vital capacity

Doesn't the level of oxygen dissolving in blood increase when vital capacity increases? And yes, due to this, energy production also increases!