<prompt> All of the following structures are located within the carotid sheath, EXCEPT?Internal jugular veinCervical sympathetic trunkVagus nerveInternal carotid aery  <response>: The carotid sheath also is a tubular fascial investment that extends superiorly between the cranial base and inferiorly to the root of the neck. The carotid sheath contains the common and internal carotid aeries, internal jugular vein, and vagus nerve . In addition, the carotid sheath contains deep cervical lymph nodes, sympathetic fibers, and the carotid sinus nerve. The cervical sympathetic trunk lies behind the sheath but is not included within it. 