Exposure of Suboccipital Muscles. The medial borders of the semispinalis capitis muscles have been reflected to expose the deeper lying midline. Here, the spinous process of the axis (C2 vertebra) and posterior tubercle of the atlas (C1 vertebra) are in view with associated musculature. Several muscles attach to the spinous process of C2, including the semispinalis cervicis, obliquus capitis inferior, and rectus capitis posterior major. The rectus capitis posterior minor muscles arise from the posterior tubercle of C1 and attach superiorly to the medial part of the inferior nuchal line. The occipital artery is a branch of the external carotid artery. It is shown here having passed deep to the splenius capitis and penetrating the semispinalis capitis. It normally passes through the trapezius muscle to supply the posterior scalp. (Image courtesy of PA Rubino)