What structure is commonly referred to as the chest or rib cage?

The thoracic cage is the structure commonly referred to as the chest or rib cage. This skeletal structure is comprised of the ribs, sternum, and thoracic vertebrae, providing protection for vital organs such as the heart and lungs. It also plays a crucial role in respiratory mechanics, allowing for the expansion and contraction needed for breathing.

In this context, the thoracic cage's primary function is to safeguard the thoracic organs while facilitating movement for inhalation and exhalation. The other options refer to different structures: the thoracic cavity is the space within the thoracic cage, the diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity and aids in breathing, while the abdominal cavity contains organs such as the stomach and intestines, not associated with the rib cage at all.