According to recent research, there is a greater understanding of all allergic processes including asthma. P
People are more aware that these processes occur as a result of hyper responsiveness that is intrinsic in some people.
Asthma occurs as a variety of symptoms: wheezing, cough, chest tightness, shortness of breath and sputum production. It happens because whenever the body recognizes an antigen (a foreign body), it endeavors to remove it or at least minimize its effect on body’s cells through inflammation. It is an immune response that is exaggerated in some people and it causes allergic asthma.
There are 2 types of responses which human body may produce: a primary response and a secondary response.
A primary response takes place on first exposure to an antigen or a foreign body. It is short lived starting after certain period of time and producing less mediators or chemicals but able to cause sensitization. A secondary response appears whenever the body is exposed again to the same antigen. It occurs readily, is more serious and produces more inflammatory mediators, which results in more signs and symptoms.
These responses lead to changes in the organism which constitute the symptoms of asthma. Inflammation reveals as few cardinal signs, such as redness, heat production, pain at the site of inflammation, swelling at the site and inability of the tissues to perform their function. When these changes appear in the lungs they enhance the symptoms of asthma. To understand physiology of asthma, we must realize that lungs are 2 big, soft organs of sponge-like consistency situated in the chest. Heart is in the center of the chest. Lungs are separated from the abdomen by the diaphragm- a strong dome-shaped muscle. It moves down when a person inhales and exhales air. During breathing our lungs change their shape: they expand during inspiration and contract during expiration.
The main function of the lungs is to supply oxygen to the blood and to remove carbon dioxide from it. The appropriate exchange of these gases between outside air and the air in the depths of the lungs depends on clear air passages. Air gets into the body through the nose and mouth and moves down into the smaller airways, called bronchi and bronchioles.
The smallest airways are microscopic in size. They end in clusters of minuscule air sacs called alveoli. There are around 300 million of these small balloon-like air sacs in the adult lung. Each of them is surrounded by a network of fine blood vessels called capillaries. The walls of these capillaries and those of the air sacs are very thin, which allows the passage of gases between the airway system and the blood. During inhalation of air, the lungs fill with air containing oxygen, that later enriches the blood.
During exhalation, carbon dioxide removed from the blood is expelled. When there is excessive mucous or secretions (due to inflammation of the airways), it leads to swelling and tightening of the smooth muscle around the airways. As a result, air flow is limited and the normal functions of the lung are affected and eventually breathing becomes more and more difficult.
Experts still do not know if all cases of asthma need a specific stimulus or not.
The immunologic pathways, various mediators, and inflammatory cells participating in allergic disorders have all been prone to intense examination. In parallel, various medications are available to the physician who manages allergic diseases, and for the first time many agents are based on an understanding of specific inflammatory pathways in allergic disease.
However, in spite of greater understanding and the new pharmacological agents, the global epidemic of allergic disorders keeps on going. It was first described with respect to asthma, but recently a greater prevalence of other allergic diseases, and of atrophy itself, has also been identified. A number of theories have turned up to explain this epidemic, ranging from misadventures with symptomatically effective superficial therapies to a reduced occurrence of protective infections in early childhood.
The former is believed to have resulted in an increase in allergic diseases due to the use of medications that merely cover up chronic inflammatory disorders, and the latter has been attributed to a failure of the developing immune system to receive the signals necessary for a protective immune response.
