Double-layered membrane surrounding the heart.

Double-layered membrane surrounding the heart.

• A. Antiemetic
• B. Ileum
• C. Duodenum
• D. Pericardium

Answer: (D)

The heart is enclosed by a double-layered membrane called the pericardium. It has an outer fibrous layer and an inner serous layer that splits into a parietal portion lining the fibrous sac and a visceral portion covering the heart itself; the space between these serous layers contains a small amount of lubricating fluid. This structure protects the heart, reduces friction as it beats, and helps hold the heart in place within the chest. The other terms refer to unrelated things: an antiemetic is a drug that prevents vomiting, while the ileum and duodenum are sections of the small intestine, not membranes around the heart.

The heart is enclosed by a double-layered membrane called the pericardium. It has an outer fibrous layer and an inner serous layer that splits into a parietal portion lining the fibrous sac and a visceral portion covering the heart itself; the space between these serous layers contains a small amount of lubricating fluid. This structure protects the heart, reduces friction as it beats, and helps hold the heart in place within the chest. The other terms refer to unrelated things: an antiemetic is a drug that prevents vomiting, while the ileum and duodenum are sections of the small intestine, not membranes around the heart.