Bronchial secretions

Bronchial secretion is a partly thin ( serous ), partly slimy ( mucous ) secretion from the glands ( glandulae bronchiales ) of the bronchi and other mucous cells ( club cells and goblet cells ) of the lower respiratory tract . Its formation is promoted by the parasympathetic and indirectly inhibited by the sympathetic .

Its physiological importance lies in the moistening of the airways (protection against dehydration) and - together with the ciliated epithelium - the cleaning of the bronchial system as well as the proteins dissolved in it in defense against infection .

In the case of infectious and tumorous diseases, bronchial secretions are obtained for microbiological and cytological examinations. When it is obtained as sputum (the expectoration when coughing ), there is inevitably contamination from the local oral and throat flora. Information about the type of sample collection and knowledge of the composition of the normal flora of the nose, mouth and throat is therefore essential for assessing the microbiological test results when clarifying infections of the deep respiratory tract. Obtaining the secretion by means of bronchoscopy and bronchial lavage or bronchoalveolar lavage (BAL) is therefore better suited for microbiological examinations , but it is also much more complex and stressful for the patient, so that mostly sputum samples are examined.

Composition of the bronchial secretion

In diseases of the deep respiratory tract, the amount and composition of the bronchial secretions change, which is called dyscrinia . So far, more than 40 proteins have been identified that mainly serve as effector substances for immune and infection defense:

Immunoglobulin A
Lysozymes , with a bactericidal effect by breaking down the murein in the bacterial wall
Lactoferrin , bacteriostatic by binding the free iron required for bacterial growth
Mucus proteinase inhibitor , also known as bronchial secretion inhibitor , with antiviral and antibacterial activity and fungicidal effect.

Individual evidence

↑ Dagmar Achleitner u. a .: Guidelines for the microbiological diagnosis of infections of the deep respiratory tract. ( Memento of the original from December 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Workshop on March 28, 2000, on infektionsnetz.at . Last accessed on December 17, 2013. @1@ 2

↑ Nikolaus N. Konietzko, H. Wendel, B. Wiesner: Diseases of the lungs . Walter de Gruyter, 1995, ISBN 3-11-012130-1 , p. 34 ( limited preview in Google Book search).

↑ D. Reinhardt, M. Götz, R. Kraemer, A. Schöni (eds.): Cystische Fibrose . Springer, 2001, ISBN 3-540-67485-3 , pp. 140 ff . ( limited preview in Google Book search).

[1] Dagmar Achleitner u. a .: Guidelines for the microbiological diagnosis of infections of the deep respiratory tract. ( Memento of the original from December 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Workshop on March 28, 2000, on infektionsnetz.at . Last accessed on December 17, 2013. @1@ 2

[2] Nikolaus N. Konietzko, H. Wendel, B. Wiesner: Diseases of the lungs . Walter de Gruyter, 1995, ISBN 3-11-012130-1 , p. 34 ( limited preview in Google Book search).

[3] D. Reinhardt, M. Götz, R. Kraemer, A. Schöni (eds.): Cystische Fibrose . Springer, 2001, ISBN 3-540-67485-3 , pp. 140 ff . ( limited preview in Google Book search).