Maintaining the health of the lungs (2)
MECHANISM of breathing and the cause of asthma
In the first part of this article, we looked at the anatomy of the respiratory system. The concluding part of what I wrote then was, after three or four more divisions, the bronchioles enter into air sacs known as alveoli.
The alveoli look like a bunch of grapes, hence the name, which means grapes in Italian. The alveoli are lined with a very thin membrane and supplied with equally tiny blood vessels known as capillaries. It is at this alveolar level that oxygen passes from the alveoli into the blood and carbon dioxide from the blood to the alveoli to be breathed out.
The bronchioles protect the alveoli when there is dehydration in that region.
The alveoli remain inflated and maintain their humidity so that they do not collapse and lose their function. The alveoli cannot afford to be dehydrated; there must always be sufficient water lining their membrane and maintaining the sacs open for the optimum exchange of the gases.
The chest cavity is separated from the abdomen by the dome-shaped diaphragm. To inhale, the diaphragm contracts and flattens pushing the abdominal contents downwards and the ribs upwards. This action creates a vacuum in the lungs that causes air to be sucked into the lungs. After the gases have been exchanged, to force out the air from the lungs, the diaphragm relaxes and assumes its dome shape once more.
As the lower ribs move downwards to their resting position elastic recoil of the lungs exerts a form of squeeze on the lungs full of air. This forces the air out of the lungs. Water plays a very important role in the breathing process. As we inhale the vacuum that draws in air into our lungs also draws in tiny molecules of water into the alveoli. This water covers the inside of the membrane of all the alveoli. The surface tension of the water helps to push air uniformly out of all the air sacs.
DEHYDRATION AS THE CAUSE OF ASTHMA
Histamine, the main neurotransmitter for the regulation of water in the body is secreted when there is shortage of water in the body. The five vital organs must have adequate supply of water even in a state of dehydration. These organs are the brain, heart, lungs, kidneys and the liver. We know that there is excess histamine in circulation when the body is dehydrated. It is histamine that causes the constriction of the bronchioles to protect the air sacs from the effects of the regional dehydration. The constriction of the bronchioles gives rise to the symptoms of an asthmatic attack.
Symptoms such as, wheezing, shortness of breath, chest tightness, cough etc. As the bronchioles constrict they also help to conserve water that would normally be lost through evaporation. The initial sign of an asthmatic attack is a telling sign to alert you that there is shortage of water in the lungs. Some attacks are known to be initiated by either emotional or physical stress. In these conditions a lot of chemical reactions take place that make a demand on the little free water available.
To be able to cope with stress and to avoid an asthma attack one may need to drink a lot of water. The same is true of eating food and exercises. There are some people who have had an asthma attack after eating or exercising. These, like the stress conditions are as a result of dehydration. When you do not drink enough water while eating, the extra water that will be needed to digest and liquefy the food will have to come from other parts of the body including the lungs. I do not have to over emphasize the point that you need to drink sufficient water when embarking on strenuous exercises. At this time there is increase in all metabolic processes in the body requiring plenty of water. You can see that all the common causes of asthma are linked to dehydration.
To treat, cure and eradicate asthma you have to drink enough water daily. Furthermore, the salt content of the mucus and fluid in the lungs and by extension, the pH, both play important roles in the development of asthma. This shall be the subject of my discussion in this column in next Thursday’s edition of the Guardian Newspaper.