Inferior-Obliquus Capitis Inferior
Lateral-Obliquus Capitis Superior
Medial-Rectus Capitis Posterior Major
posterior atlanto-occipital membrane and the posterior arch of the atlas form
the floor of the triangle. The semispinalis capitis muscle is the roof of the
triangle. The Suboccipital Triangle contains the
vertebral artery and the suboccipital nerve. This is the transition point of
the second and third portion of the vertebral artery.
In the suboccipital region the vertebral arteries each have a winding course before ascending and anastomosing with each other to form the basilar artery (vertebrobasilar system). The basilar artery is the main vascular supply to the brainstem, posterior cerebrum, and cerebellum.
The winding course of the
vertebral artery is protective. The vertebral artery is seldom violated by neck
or head trauma.