Mucociliary clearance

Mucociliary clearance, and mucociliary cleaning, mucociliary apparatus or Mucociliar clearance ( MCC ), called derived from mucus ( phlegm Latin ), cilia ( Flimmerzelle of the surface epithelium in the respiratory tract) and clearance ( engl. cleaning), refers to the self-cleaning mechanism of the bronchi.

The main bronchi to the terminal bronchioles ( the end of the air-conducting portion ) are lined with respiratory epithelium, also trachea, larynx, nose, and wide sections of the pharynx. On it are ciliated cells bearing on their surface hair-like structures ( cilia ). The cilia are surrounded by a thin liquid layer of mucus. Then there is a second viscous mucus layer, stick in the foreign particles and microorganisms. Within the thin liquid layer of mucus, the cilia perform coordinated movements toward the pharynx. Thus, the viscous mucus layer is carried away with their cargo toward the mouth where it is swallowed or coughed up.

For a good mucociliary cleaning are the number of cilia, their structure, activity, and coordinated movement. Optimum functioning of the purification requires a temperature of 37 ° C and an absolute humidity of 44 mg / l corresponding to a relative humidity of 100 %. In case of insufficient heat and humidity, the ciliated cells make their transport function after a short time. The bacterial bacterial colonization is facilitated under these conditions. Lung infections and damage to the lung tissue can be the result.

High humidity enhances the function of the mucociliary clearance. Two methods for supporting the cleaning are the active and passive humidification, which are used in particular in mechanical ventilation.