Which of the following organs is not hollow?

• A. Liver
• B. Uterus
• C. Gallbladder
• D. Stomach

Answer: (A)

The main idea here is differentiating hollow organs from solid ones. A hollow organ has a cavity or lumen that holds contents, while a solid organ is made up of tissue without a central cavity.

The liver is a solid organ. Its structure is composed of hepatocytes arranged into lobules with a network of vessels, and it lacks a true internal cavity. In contrast, the uterus has a distinct hollow cavity (the uterine cavity) lined by endometrium; the gallbladder is a sac with a lumen that stores bile; and the stomach is a large hollow chamber with a continuous digestive lumen. Therefore, the organ that is not hollow is the liver.