Fig. 1
From: An anatomical study of arcuate foramen and its clinical implications: a case report
Photograph of specimen A shows a posterior view of the sub-occipital region showing the atlas with symmetrical complete bilateral dorsal osseous bridges; the lateral osseofibrous bridge; and the oval opening between the two bridges. Also, the passage of VA through the tunnel formed by the dorsal and lateral bridges. The sub-occipitall nerve (C1 dorsal ramus) along with branches of vertebral artery emerging from the oval opening. 1. Dorsal bridge; 2. Vertebral artery; 3. C1 dorsal ramus; 4. Lateral bridge; 5. Rectus capitis posterior minor; 6. C2 dorsal root ganglion; 7. C2 dorsal ramus; 8. C2 ventral ramus; 9. Branches of VA; 10. Dorsal tubercle of atlas; 11. Dorsal arch of atlas