ABSTRACT

There are two lungs, one on each side. The left one has two lobes, the lower lobe and the upper lobe, part of the upper lobe being known as the lingula (Latin – tongue), a tongue-like part of the lung which comes in front of the heart. On the right hand side there are three lobes, the upper, middle and lower lobes, each supplied with their own bronchus (tube leading into the lung). The right lung constitutes approximately 55% of the total lung volume, the left lung 45%. It is smaller because the heart is almost invariably situated in the left side of the chest and occupies the rest of the space that the lung would otherwise occupy; the exception being with dextrocardia, when the side of the organs is reversed – a very rare situation.