What does the thorax refer to in mammals?

The thorax in mammals refers to the area between the neck and the abdomen. This part of the body is critical as it houses important organ systems, including the heart and lungs, which are protected by the rib cage. The thorax also includes the sternum and the thoracic vertebrae, playing a vital role in the respiratory system by facilitating breathing and providing structural support to the upper body.

Understanding the thorax is essential for studying various biological processes, such as circulation and respiration, as well as for recognizing how these systems interact with other areas of the body. The definition of the thorax as the section between the neck and abdomen clearly distinguishes it from the other options, which describe different areas of the body or are too broad to define this specific region accurately.