MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

CHAPTER 6. THE RESPIRATORY PROCESS AND ITS PATHOLOGY

RESPIRATORY SYSTEM DISEASES

BRONCHITIS

1. ACUTE BRONCHITIS

Acute Bronchitis is an acute inflammation of the bronchial mucosa. It is one of the most common respiratory disorders, accounting for at least one-third of all respiratory tract diseases.

Infectious agents—Viruses and Bacteria—play the primary role in The Development of acute bronchitis. The disease can also be triggered by various physical factors (inhalation of cold or hot air) or chemical damaging agents (inhalation of nitrogen oxide, hydrogen sulfide, ammonia, chlorine or bromine vapors, and other toxic substances). Involvement of the Trachea and Bronchi in the pathological process is frequently observed in patients with acute respiratory viral infections (Influenza, parainfluenza, Adenoviruses).

Depending on the aforementioned damaging factors, the inflammatory process may localize in the trachea and large bronchi (tracheobronchitis), medium-sized or small bronchi (bronchitis), and bronchioles (bronchiolitis). Inflammatory mucosal changes combined with increased mucus production often lead to impaired bronchial patency, which is a contributing factor to the progression of acute bronchitis into a chronic form.

In mild cases, the pathological changes are confined to the mucous membrane, whereas in severe cases, they involve all layers of the bronchial wall. The mucosa appears edematous and hyperemic, with a surface layer of mucous, mucopurulent, or purulent exudate. In severe forms of the disease, mucosal hemorrhages frequently occur, and the exudate may acquire a hemorrhagic character. In certain instances, complete obstruction of the lumen of small bronchi and bronchioles by secretion is possible.