Final answer:
The body of the cervical vertebra is slanted at a 45 degree angle, allowing for a range of motion. The medius and posterior scalenus anterior muscles create cervical flexion and cervical extension.
Step-by-step explanation:
The body of the cervical vertebra is slanted at a 45 degree angle. This angle allows for a range of motion in the neck for flexion, extension, lateral flexion, and rotation. The medius and posterior scalenus anterior muscles in the neck function to create cervical flexion and cervical extension, respectively.