Head and chest anatomy. Historical artwork of a human head and upper torso, cut vertically in half and seen sideways. In the head, layers of skin and bone cover the brain (green). At the front of the head (blue area) is the tongue, palate, and nasal cavity. In the brain, the corpus callosum (pale green, centre) connects the two hemispheres, while below it the brainstem connects to the spinal cord (pale green, running down back). This is enclosed by spinal bones (vertebrae, blue at left, green at right). In the chest (yellow) the trachea is the rigid tube in front of the oesophagus (collapsed). The breastbone is in front of the heart (internal chambers seen here, black), which lies between the lungs (not seen). The liver is at bottom, below the diaphragm.