Body organs

What is the largest cavity in the skull that contains the brain?

Which cavity is located inside the lower mediastinum and surrounds the heart?

Which cavity is in the trunk below the diaphragm and can be divided into abdominal and pelvic cavities?

Which cavity is surrounded by pelvic bones and can refer to both the narrow sense and the broad sense?

Which cavity extends from the cranial cavity inside the spinal cord?