Upper body anatomy. Glass-effect human male body in side view, showing the internal anatomy of the upper body and head. Inside the head is the brain (top). The backbone (spine) runs down the back of the body from the base of the head to the pelvic bone. Inside the chest is the ribcage (upper centre), which protects the heart and lungs. At the bottom of the ribcage is the stomach where food is digested before passing into the intestine (lower centre). The small and large intestines fill the abdominal cavity above the pelvic bone.