Definition of COUNTERBORE. : to form a counterbore in: enlarge (part of a hole) by means of a counterbore.ADVERTISEMENT.efinition of COUNTERBORE. 1. : a flat-bottomed enlargement of the mouth of a cylindrical bore. 2. : a drill for making a counterbore â compare countersink.
The vestibulocochlear nerve (auditory vestibular nerve) , known as the eighth cranial nerve, transmits sound and equilibrium (balance) information from the inner ear to the brain.
Chapter 7 - Lower cranial nerve function. The lower cranial nerves are involved in pharyngeal and laryngeal function as well as in movements of the neck and tongue. Damage usually manifests as problems with speech and swallowing.These nerves arise from the medulla and, in the case of the accessory nerve (CN XI), the spinal cord.These nerves are commonly affected by conditions damaging the medulla, but bilateral damage to corticobulbar connections can create motor problems that affect tongue and pharynx movement and speech.oth the glossopharyngeal and vagus nerves (CN IX and X) have taste and somatic sensory functions that are not routinely examined. However, the taste function in the glossopharyngeal nerve (CN IX) can be examined if there is suspicion of damage to the nerve (vagus nerve taste function cannot be tested).