Which statement best describes the heart?

Which statement best describes the heart?

• A. It is a muscular, hollow organ weighing less than 1 pound
• B. It is a solid organ weighing more than 5 pounds
• C. It is a nerve tissue organ weighing about 1 pound
• D. It is a rigid structure weighing 2 pounds

Answer: (A)

The heart is a muscular, hollow pumping organ. It’s made of cardiac muscle and has chambers that fill with blood and eject it under pressure, so it functions as a pump rather than a solid block of tissue. In an average adult, it weighs about 250–350 grams, which is roughly a half to three-quarters of a pound—consistently less than a pound. It isn’t a solid organ, it isn’t nerve tissue, and it isn’t rigid; its walls must be able to stretch and contract to move blood through the heart and to the rest of the body. That’s why the description of a muscular, hollow organ weighing less than a pound best fits the heart.

The heart is a muscular, hollow pumping organ. It’s made of cardiac muscle and has chambers that fill with blood and eject it under pressure, so it functions as a pump rather than a solid block of tissue. In an average adult, it weighs about 250–350 grams, which is roughly a half to three-quarters of a pound—consistently less than a pound. It isn’t a solid organ, it isn’t nerve tissue, and it isn’t rigid; its walls must be able to stretch and contract to move blood through the heart and to the rest of the body. That’s why the description of a muscular, hollow organ weighing less than a pound best fits the heart.