(6)hypoglossal nerve and its descending branch Meningeal branch Hypoglossal nenre oit)(n hypoglossal canal Inferior ganglion of vagus nerve Styloglossus muscle Supenor longitudinal muscle Hypoglossal nucleus Re Transverse and vertical muscles Occipital condyle Inferior longitudinal A muscle ventral rami of C1. 2 3 form cervical plexus Superior cervical Genioglossus muscle sympathetic ganglion Geniohyoid muscle Hyoglossus muscle Supenor root of ansa cervicalis Intemal carotid artery Thyrohyoid muscle Inferior root of ansa cervical Ansa cervicalis 行程:从二腹肌后腹深面进入颈动脉三角呈弓形向前越过颈内、外动脉浅面 二腹肌后腹深面→下颌下三角。 分支:有颈袢下根(舌下神经降支、至甲状舌骨肌神经和心支等。（6）hypoglossal nerve and its descending branch • 行程：从二腹肌后腹深面进入颈动脉三角呈弓形向前越过颈内、外动脉浅面 →二腹肌后腹深面→下颌下三角。 • 分支：有颈袢下根(舌下神经降支)、至甲状舌骨肌神经和心支等