What does the thoracic cavity house in mammals?

The thoracic cavity is a crucial component of the mammalian anatomy, as it is specifically designed to house vital organs involved in respiration and circulation. Among these organs are the lungs, which are critical for gas exchange, allowing oxygen to enter the bloodstream and carbon dioxide to be expelled. Positioned alongside the lungs is the heart, responsible for pumping blood throughout the body and facilitating the transport of nutrients, gases, and waste products.

This anatomical arrangement in the thoracic cavity highlights the protective rib cage that surrounds these organs, providing structural support while also allowing for the necessary expansion during inhalation and exhalation. The diaphragm, a muscle located beneath the thoracic cavity, plays a significant role in breathing by contracting and relaxing to help draw air into the lungs.

Although some of the other options mention organs associated with the thoracic cavity, they do not accurately reflect the primary contents housed within it. For example, while the stomach and liver are essential organs, they are situated in the abdominal cavity rather than the thoracic cavity, and ribs are not organs but rather part of the skeletal structure that protects the thoracic cavity itself. The correct answer identifies the lungs and heart, which are indeed housed within the thoracic cavity and paramount to the functioning of the mammalian