Pleural effusion - image description

The diagram is a cross-section of the top half of a person. Leading from the back of the throat is a tube known as the trachea. This leads down into the top of the chest area. At this point the trachea divides into two tubes, the left bronchus and the right bronchus. They lead into two lungs, one on either side of the body. The lungs fill most of the chest area. The bronchi are like tree trunks with smaller tubes or branches leading off them. Surrounding the lungs are two thin membranes known as the pleura. The space between the two layers is called the pleural cavity. On one side there is fluid in the pleural cavity so the lung is smaller. The fluid is the pleural effusion. The ribs surround the lungs.