The fetal pig can be divided into four main regions: head, neck, thorax, and limbs. The head region includes the brain, eyes, ears, nose, and mouth. The neck region is located between the head and thorax and contains the trachea, esophagus, and major blood vessels. The thorax region contains the heart, lungs, and other thoracic organs. The limb region includes the forelimbs (arms) and hindlimbs (legs).