Vesicular Breathing

VESICULAR BREATHING, the normal respiratory sound heard during auscultation over healthy lung tissue. It consists of an implicit blowing sound occupying the entire period of inhalation, and a short, indefinite sound during exhalation, heard for 1/3 of its period. Theories of the origin of vesicular breathing: according to Laennec, vesicular breathing is the result of the friction of the inhaled air stream against the walls of the bronchioles and infundibula; according to Baas, it is laryngotracheal breathing modified by passing through the lung tissue; according to Gerhardt (the generally accepted view), it is the local inspiratory movement of the lung tissue. The short expiratory sound can be interpreted either as a modified and weakened laryngotracheal sound or as a consequence of the local expiratory movement of the lung (Sahli). Within physiological limits, there are various fluctuations in the strength and shades of vesicular breathing. In children, it sounds sharp and high-pitched due to the greater elasticity of the lung tissue and the lesser thickness of the chest wall ("puerile breathing"). In adults, the loudest vesicular breathing is heard on the anterior and upper surface of the chest, especially on the right; conversely, posteriorly over the lower lobes of the lungs, in a resting position, it is weakened. The thicker the layer of soft tissues on the chest and the more superficial the breathing, the weaker the vesicular breathing. Pathological changes in vesicular breathing: Strengthening of breathing, accompanied by some change in the character of the heard sound (harsh or sharp vesicular breathing), depends on changes in the conditions of air passage through the bronchi or on changes in the conditions of sound conduction. It can be diffuse (catarrh of the small bronchi) or localized (inflammatory infiltrations of the lungs, cicatricial processes in the vicinity of tumors, etc.). Vesicular breathing with prolonged expiration is observed in diffuse bronchitis, in emphysematous patients, and during asthmatic attacks; it depends on the swelling of the mucous membrane of the respiratory tract. Saccadic breathing is called vesicular breathing that is interrupted by pauses or weakenings. With the correct function of the neuromuscular respiratory apparatus, it arises due to the formation of obstacles to the passage of the air stream through the respiratory tract. Weakening of vesicular breathing is observed in all cases of difficulty in inspiratory expansion of the lungs: in emphysema, due to the loss of elasticity by the lung tissue; in the presence of obstacles in the trachea or larynx; during compression of the bronchi by an aneurysm, tumor, or scar tissue (contracting chronic processes); and due to compression of the lung during exudative pleurisy, hydrothorax, and pneumothorax.