Pores of Kohn

The Pores of Kohn (also known as interalveolar connections) are discrete holes in walls of adjacent alveoli. Cuboidal type II alveolar cell usually forms part of aperture.

The Pores of Kohn take their name from the German physician Hans Kohn [1866-1935] who first described them in 1893.

They are absent in human newborns. They develop at 3-4 years of age along with Canals of Lambert during the process of thinning of alveolar septa.

They function as a means of collateral ventilation; that is, if the lung is partially deflated, ventilation can occur to some extent through these pores. They also allow air to pass through, this provides collateral ventilation and even distribution of air to the alveoli. They equalize the pressure in adjacent alveoli and thus play an important role in prevention of collapse of lung. The pores also allow the passage of other materials such as fluid and bacteria, which is an important mechanism of spread of infection in Lobar pneumonia and spread of fibrin in the grey hepatisation phase of recovery from the same.

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