The occipital artery is one of the posterior branches of the external carotid artery that arises below the posterior belly of the digastric muscle. At its origin, the occipital artery passes posteriorly to the level of the posterior belly of the digastric muscle. Then it crosses the internal carotid artery, the internal jugular vein, and three cranial nerves - the hypoglossal nerve (CN XII), vagus nerve (CN X) and accessory nerve (CN XI).