The number of vertebrae in the human vertebral column is

Analyze the question: You're asked for the total number of vertebrae in the human vertebral column (backbone).

Concept: The human vertebral column is divided into five regions. The count for each region is:

| Region | Number of vertebrae | |---|---| | Cervical (neck) | 7 | | Thoracic (chest, with ribs) | 12 | | Lumbar (lower back) | 5 | | Sacral (fused) | 5 | | Coccygeal (tail bone, fused) | 4 |

Solution:

7 + 12 + 5 + 5 + 4 = 33

Note that in an adult, the 5 sacral vertebrae fuse into one bone (the sacrum), and the 4 coccygeal vertebrae fuse into the coccyx. So an adult has only 26 separate bones, but the standard count of vertebrae is 33.

Checking the options:

• A. 30: not the standard count
• B. 33: matches our total
• C. 38 and D. 39: too high

Exam tip: Remember the pattern 7-12-5-5-4. The first three numbers match the times many people have breakfast (7), lunch (12), and dinner (5). Then the "5-4" for the fused sacrum and coccyx finishes it. Also note that the cervical region has 7 vertebrae in almost all mammals, even giraffes!