The Homepage for Children's Health
Asthma in Children Childhood Diseases The Baby Page Vaccination Food and Drink Other Problems of Childhood
Lung Lingo Lungs:- We have two of these, one on each side of the chest. Air enters them when we breathe in, and exits when we breath out. The blood which comes back to the heart after delivering oxygen all over the body, and collecting carbon dioxide, is pumped to the lungs via the Pulmonary arteries for gas exchange, the main function of the lungs. Trachea:- This is the main windpipe, and extends from the larynx in the neck, into the chest. Here it divides into two bronchi, the left and the right, which each carry air to and from the corresponding lung. Bronchi:- The two main bronchi and their divisions. As the bronchi divide they get smaller in diameter. The walls of the larger bronchi contain cartilage, which makes them stiff; the smaller bronchi have muscle tissue and connective tissue only. The small airways are chiefly involved in asthma. The alveoli:- At the end of the bronchial tree lie the alveoli, small air cells where the vital work of gas exchange gets done. Oxygen from inspired air is taken by the blood flowing past, and carbondioxide given up into the air, which is then breathed out. Bronchospasm:- The condition of narrowing of the small airways, so that free movement of air is obstructed, and the work of breathing is increased. The essential feature of asthma bronchospasm is reversibility. Hypoxemia (sometimes called hypoxia):- The condition where gas exchange is badly affected, to the extent that the body is not getting its requirements of oxygen. The blood contains low concentrations of oxygen, and all organs suffer the shortage of oxygen. This is a serious condition, and requires prompt, aggressive, treatment.

Asthma Basics

The problem in asthma, which causes all the difficulties to the sufferer, is a narrowing of the airways. But asthma isn't just narrow airways. We have realized this in the last few decades, and this new understanding has immeasurably improved the lives of people with asthma.

The narrowing is not in the windpipe, nor its two large divisions which each enter a lung. The narrowing is in the sub sub sub divisions of these bronchi, which are small tubules supplying the air cells of the lung. The narrowing is such that it obstructs the exit of air from the lungs, resulting in air trapping. This air trapping causes a condition called hyperinflation of the lungs.

The narrowing occurs in response to certain stimuli, or triggers, - smells, smoke, cold air, pollen, gases, fumes, exercise, etc. The triggers vary from person to person. However, the reason theses everyday stimuli are able to stimulate a narrowing of the airways is a condition called bronchial hyperreactvity.

As the name suggests, the bronchi react abnormally strongly to stimulus, and this is caused by an inflammation in the walls of the bronchi. This inflammation, and the resulting bronchial hyperreactivity, differentiate people with asthma from normal people.

Thus, treatment that relieves the narrowing of the airways (bronchospasm), is only half the job. Proper asthma treatment requires the reduction of airway inflammation. The concept of asthma as an inflammatory disorder has revolutionized asthma therapy and made it possible for children with asthma to live full, normal lives.

An important thing we have learnt is that asthma causes a slow reduction in lung function. This is because the inflammation is accompanied by the laying down of scar tissue.

The airway narrowing so caused is irreversible. These persons become limited in their activity more and more, and eventually have lifestyle restrictions. To prevent this, even asthma that is not causing acute symptoms must be treated.

Last revision: July 15, 2007

Mehta Childcare home      The Baby Page      Vaccination
Childhood diseases      Asthma     Food and drink
Childhood problems     About Dr Parang