An angiographic study of the distal pa of the circle of Willis requires access to the veebral aery. Access to this aery can be obtained the?

The suboccipital triangle lies in the neck at the base of the skull. The suboccipital triangle is bounded by the inferior oblique, rectus major, and superior oblique muscles. The veebral aery can be found within the suboccipital triangle, lying on the posterior arch of the atlas, lateral to the midline, typically at about the level of the lower poion of the ear lobe. Care should be taken in accessing the vessel, since the first cervical nerve lies between the veebral aery and the posterior arch of the atlas.