Which structure is located between the lungs and thorax?

The diaphragm is a dome-shaped muscle that plays a crucial role in respiration by separating the thoracic cavity, which houses the lungs and heart, from the abdominal cavity. It sits at the base of the thorax and moves downward during inhalation, generating negative pressure that draws air into the lungs. This unique position between the lungs and the thorax allows it to perform its function effectively, facilitating the breathing process.

The rib cage serves as a protective structure surrounding the thoracic organs but does not sit between the lungs and thorax like the diaphragm does. The pleura are membranes that envelop the lungs; although they are situated adjacent to the lungs, they are not the muscular structure responsible for the mechanical process of breathing. The bronchus refers to the air passages that branch from the trachea to the lungs, which are not located between the lungs and the thoracic cavity. Therefore, the diaphragm is distinctly identified as the structure that resides in the space separating these two important areas.