What is contained within the pericardial cavity?

The pericardial cavity specifically contains the heart. This cavity is a fluid-filled space that surrounds the heart and is encased by a double-layered sac known as the pericardium. The primary function of the pericardial cavity is to allow the heart to move freely as it beats, while providing a protective environment that reduces friction between the heart and surrounding structures. The fluid within the cavity also helps to cushion the heart, preventing damage during the contraction and relaxation phases of the heartbeat.

The other options listed, such as the lungs, stomach, and spine, are located in different anatomical cavities. The lungs are situated within the thoracic cavity but are enclosed by the pleural cavities, while the stomach is found within the abdominal cavity. The spine is part of the vertebral column and is housed within the spinal cavity. Each of these structures is associated with different protective membranes and spaces that serve their unique functions, which distinguishes them from the pericardial cavity dedicated entirely to the heart.