In the last 17 years, the number of sufferers in the U. S. has doubled to more than 14 million people. The victim wheezes and coughs.
Severe attacks can be life-threatening.
The Mechanism An attack of asthma begins when an allergen is inhaled. Binding triggers exocytosis of the mast cells with the release of histamine and leukotrienes These substances cause the smooth muscle cells of the bronchi to contract narrowing the lumen of the bronchi. This is the early phase . This is the late phase . With repeated attacks, the lining of the bronchi becomes damaged.