What is the name of the ridge running down the center of the sacrum?

• A. Medial sacral crest
• B. Lateral sacral crest
• C. Sacral canal
• D. Sacral promontory

Answer: (A)

The ridge running down the center of the sacrum is the medial sacral crest. It sits along the dorsal midline and is formed by the fused spinous processes of the sacral vertebrae (S1–S5), creating a central crest that you can feel along the back of the sacrum. In contrast, the lateral sacral crests run along the sides and are formed by the fused transverse processes, the sacral canal lies within the sacrum as a continuation of the vertebral canal, and the sacral promontory is the anterior brim at the top of the sacrum. So the midline, dorsal ridge is the medial sacral crest.