The torso refers to the entire body, both front and back, with the upper torso referring to the area between the stomach and the neck, and the chest refers to the front part of the body between the neck and the abdomen.. The chest only refers to the front of the upper part of the body and the upper torso refers to both the front and back of the upper part of the body.
The chest is also referred to as the area that is enclosed by the bones of the rib and the sternum. The torso is also known as the trunk of the human body.
The bones of the chest and the upper back form the rib cage, which protects the heart and the lungs. The rib cage is also what helps to position the head, neck, shoulder and arm bones to the trunk of the body or torso. Muscles also attach to these bones from the head and the arms to allow these body parts to move around. The chest bones are also responsible for supporting the upper body's weight.
There are 12 pairs of ribs in the human body that extend both laterally and anteriorly from the thoracic vertebrae. The seven superior pairs of ribs are connected directly to the sternum via costal cartilage.