About the suboccipital part of the vertebral artery and the neighboring bone-joint and nerve relationships.

Length measurements, nerve-vessel relationships, and vessel relationships to articulations and the dura mater were examined in 65 head and neck halves. The paramedian distance of the vertebral artery (midpoint) is a mean of 15.8 mm on the right, and a mean of 17.3 mm on the left, in the area of the intervertebral symphysis C2-C3 at the transverse foramen of the axis the artery has a paramedian mean distance of 17 mm. After the exit of the artery from the axis four types of loop formations of the axoatlantal part and their occurrences are described. Also, the atlantal part of the artery was studied: the overlapping of the posterior arch of the atlas was 5.14 (0 to 13) mm. The length of the axoatlantal part of the vertebral artery was a mean of 39 mm, and the length of the atlantal part was a mean of 44 mm. Besides the measurements of the outer diameter of the artery, the branches and anastomoses of the V(3) segment, nerve-vessel and nerve-joint relationships of the artery, and some veins of the craniocervical junction are described. All findings are discussed in relation to their clinical significance.