Question

The _______ cavities are along the back in humans. The cavity _____ is one of the body cavities on the dorsal side.

Answer 1

Sentence 1 = Dorsal
Sentence 2 = Cranial

Dorsal means the back side, I always remember it because I think of a dorsal fin on a dolphin and how it is on their back.
Also the cranial cavity is your brain area which leads to your spinal cord which is in the back side of the body.