Which BL point lies over the first posterior sacral foramen?

• A. BL 31
• B. BL 32
• C. BL 34
• D. BL 33

Answer: (A)

The bladder channel along the sacral region uses the posterior sacral foramina as landmarks. Each of the first four foramen levels corresponds to one bladder point: BL 31 sits exactly over the first posterior sacral foramen, BL 32 over the second, BL 33 over the third, and BL 34 over the fourth. So the point over the first posterior sacral foramen is BL 31. This anatomical alignment explains why that specific BL point is the correct choice for the first foramen.