What forms the floor of the suboccipital triangle?

What forms the floor of the suboccipital triangle?

• A. Occipital bone
• B. Posterior arch of atlas; posterior atlanto-occipital membrane
• C. Dorsal ramus C1
• D. Posterior longitudinal ligament

Answer: (B)

Understanding the floor of the suboccipital triangle comes down to which structures lie directly beneath the three muscles that form its boundaries. The floor is a combination of bone and membrane that connect the atlas to the occipital bone: specifically, the posterior arch of the first cervical vertebra (atlas) and the posterior atlanto-occipital membrane spanning to the occipital bone. This membrane bridges the gap between the atlas and the occipital bone, completing the floor of the triangle. The other structures either form the walls around the triangle or lie within its depth, but they do not constitute the floor.

Understanding the floor of the suboccipital triangle comes down to which structures lie directly beneath the three muscles that form its boundaries. The floor is a combination of bone and membrane that connect the atlas to the occipital bone: specifically, the posterior arch of the first cervical vertebra (atlas) and the posterior atlanto-occipital membrane spanning to the occipital bone. This membrane bridges the gap between the atlas and the occipital bone, completing the floor of the triangle. The other structures either form the walls around the triangle or lie within its depth, but they do not constitute the floor.