Tegmentum contains the red nuclei and the reticular formation . Red nucleus functions with basal nuclei and cerebellum to coordinate muscle movements. Tegmentum integrates info from the cerebrum and cerebellum and issues involuntary motor commands to the erector spinae to help maintain posture.
Tectum contains the corpora quadrigemina : superior and inferior colliculi, visual and auditory reflex centers
CN VIII, part ( vestibulocochlear ): balance and hearing
CN IX ( glossopharyngeal ): posterior 1/3 of taste, monitors B.P. and [gas] in major blood vessels, controls swallowing muscles (ANS)
CN X ( vagus , the “wanderer”): motor to soft palate, pharynx, and esophagus and viscera in thorax and abdominopelvic regions, unconscious sensations from viscera, etc.- important for ANS function (major ANS)
CN XI ( accessory ): some motor fibers from lateral gray horns of C1-C5. Motor to voluntary swallowing muscles, laryngeal muscles to vocal cords. Motor to trapezius and sternocleidomastoid. Accessory to vagus.