MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Ya.I. Fedonyuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

CHAPTER 6. THE RESPIRATORY PROCESS AND ITS PATHology

RESPIRATORY SYSTEM DISEASES

BRONCHIECTASIS

Bronchiectasis is an acquired (or, in rare cases, congenital) disease characterized by a chronic purulent process in irreversibly altered (dilated, deformed) and functionally impaired Bronchi, predominantly in the lower lobes of the Lungs.

The primary morphological substrate of the pathological process consists of regional dilations of the bronchial tree (bronchiectasis).

A decrease (whether congenital or acquired) in the resistance of the bronchial walls to so-called bronchiectatic forces—such as increased intrabronchial pressure during coughing, stretching of the bronchi due to accumulated exudate, and Pulmonary Atelectasis—leads to a persistent widening of the bronchial lumen. This triggers inflammation within the bronchi, the progression of which causes irreversible structural Changes in the bronchial walls: remodeling of the mucous membrane accompanied by the complete or partial destruction of the ciliated epithelium and Impairment of the bronchial clearance function, alongside degeneration of cartilaginous plates and Cytology/cytology/32.html">Smooth Muscle tissue (which are replaced by fibrous tissue). These factors ultimately drive The Development of regional bronchial dilations, known as bronchiectasis.

Bronchiectasis impairs the cough clearance mechanism, leading to stagnation and infection of secretions within the dilated bronchi, as well as the development of a chronic purulent process characterized by periodic exacerbations. This constitutes the second major pathogenetic factor in bronchiectasis. Suppuration within the established

bronchiectatic cavities forms the core of bronchiectasis as a disease.

The altered secretions accumulate in the lower sections of the bronchial tree, flowing downward under METABOLISM/18.html">The Influence of gravity. This explains why the pathological process predominantly localizes to the lower PARTS OF THE lungs.

Bronchiectasis is characterized by a protracted course with recurrent flare-ups during the spring and autumn periods. These exacerbations are most commonly triggered by hypothermia, Influenza, or respiratory infections. Sclerotic changes in the lungs and emphysema (resulting from concurrent diffuse Bronchitis) gradually develop and progress, ultimately leading to respiratory failure and symptoms of right-sided Heart Failure.