Across
3. Creates a top & bottom
6. Beneath the surface
9. Underside of the foot
10. fixed line of reference
12. Directed away from a center
13. Pertaining to a center
15. Lying face up
16. Farther from the trunk
17. Situated away from a center
19. Directed toward a center
20. Above, higher than
21. farther from the midline
Down
1. Universal starting point
2. Creates a front & back
4. closer to the midline
5. Closer to the surface
7. Lying face down
8. Below, lower than
9. behind a structure
11. Top side of a structure
14. In front of a structure
18. Closer to the trunk
20. Creates a left & right side of body