View of left posterolateral neck and infratemporal fossa. Most of the ramus of the mandible has been removed. Posterior to the ramus is the facial nerve and external carotid artery. Both are contained within the substance of the parotid gland, which has been removed. The external carotid gives rise to its terminal branches near the neck of the mandible. Here, the maxillary artery passes into the infratemporal fossa while the superficial temporal artery crosses the root of the zygomatic arch to the lateral scalp region. Within the infratemporal fossa, the inferior alveolar and lingual nerves emerge between the lateral and medial pterygoid muscles. The lingual nerve is the more superior of the two and enters the mouth to supply general sensory innervation to the anterior two-thirds of the tongue and mucous membrane of the floor of the oral cavity. The inferior alveolar nerve gives rise to the nerve of the mylohyoid (motor to the mylohyoid and anterior digastric muscles) before it enters the mandibular foramen. It provides general sensation to the mandibular teeth. Posterior to the condyle of the mandible is the external auditory canal. Posterior to this is the mastoid process to which attaches the longissimus capitis muscle superficially and the posterior digastric on its medial surface. The posterior digastric muscle narrows to an intermediate tendon that unites with the greater horn of the hyoid bone. The hypoglossal nerve passes deep to the intermediate tendon and mylohyoid muscle to enter the floor of the mouth. It provides the motor supply to the intrinsic and extrinsic muscles of the tongue, except for the palatoglossus muscle. Descending obliquely on the upper external surface of the internal jugular vein is the spinal accessory nerve. Posterior to the vein is the levator scapulae muscle. The occipital artery, a branch of the external carotid, is shown passing deep to longissimus and coursing medially on the surface of the obliquus capitis superior and semispinalis capitis muscles. It penetrates the overlying splenius capitis and trapezius muscles to ascend onto the posterior scalp in company with the greater occipital nerve. (Image courtesy of AL Rhoton, Jr.)