Healthy lungs and heart. Coloured X-ray of the chest of an 11-year-old boy showing normal lungs and heart. The lungs (dark bluish areas to the left and right of the spine) are enclosed by the ribs (pink bands). Both lung fields are clear with opacities (greenish yellow) due to the bronchi and pulmonary blood vessels (at the midcentre of each lung field). The heart (yellow) is protruding to the right of the spinal column and the diaphragm (green) is clearly visible at lower centre. Skeletal features include the thoracic spine (upper centre), the clavicles (collar bones; bones on top left and right slanting between shoulders and rib cage).