_Pharynx_: The pharyngeal plexus is a mixture of sensory axons from the glosso-pharyngeal, motor components from the vagus and probably sensor from the same nerve, and sympathetic branches from the superior cervical ganglion. All of these may be influenced by the upper cervical adjustment. _Larynx_: According to anatomy the larynx is innervated by the superior and inferior, or recurrent, branches of the vagus and by sympathetic branches from the superior cervical ganglion. Clinically the sixth cervical adjustment cures laryngitis and aphonia. The explanation probably lies in the fact that the thyroid branches of the middle cervical ganglion, lying in front of the transverses of the sixth, communicate within the thyroid gland with the recurrent laryngeal and with the external laryngeal branch of the superior laryngeal. _Thyroid Gland_: “The nerves to the thyroid are amyelinic and are derived from the middle and inferior ganglia of the sympathetic.” (Gray.) The middle cervical ganglia are situated in front of the transverse processes of the sixth cervical vertebra. Clinically, the sixth cervical reaches goitre. _Muscles of Neck_: The platysma is supplied by the facial nerve; the sternomastoid by the spinal accessory and cervical plexus; the infrahyoid region by the first three cervical nerves; the suprahyoid region by the facial and the ansa cervicalis; the anterior and lateral vertebral muscles by the cervical nerves from second to seventh inclusive, but especially the second, third, and fourth. It will be seen that muscular disturbance in the neck may result from any cervical subluxation. Torticollis, which usually involves the sternomastoid, yields to the second cervical most frequently. _Lymph Nodes of Head and Face_: These lymph nodes are controlled by the cervical sympathetic. Pathological changes in one or more nodes requires careful cervical palpation to determine the presence of a subluxation away from the affected side. _Muscles of Back_: The trapezius is innervated by the spinal accessory and by the third and fourth cervical nerves; the latissimus dorsi by the sixth, seventh, and eighth cervical through the middle or long subscapular. Occasionally a tender nerve, traceable from the lower reaches of the latissimus to the cervical region has mislead the practitioner into imagining a cervical connection over the back with internal viscera. The second layer of the back is supplied by the third, fourth, and fifth cervical nerves. The third layer is innervated by the middle and lower cervical and upper three thoracic nerves except the serratus posticus inferior which is supplied by the ninth, tenth, and eleventh thoracic. The fourth and fifth layer are supplied by the posterior primary divisions of the spinal nerves and any given section of these layers may be traced to a vertebra directly above, or cephalad.