Question

the thoracic cavity is separated from the abdominopelvic cavity by the: spinal column umbilicus quadrants diaphragm

Explanation:

The thoracic cavity, which contains the heart and lungs, is separated from the abdominopelvic cavity, which holds digestive and reproductive organs, by the diaphragm. The diaphragm is a dome - shaped muscle that plays a crucial role in respiration.

Answer:

diaphragm