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.
Functions. Each of the 12 cranial nerves has a specific function that helps the brain control the actions of the body. 1  The olfactory nerve is involved in the sense of smell. 2  This nerve has access to the cerebral cortex, but does not pass through the thalamus like other cranial nerves.he cranial nerves appear in pairs at the bottom surface of the brain. Their functions vary, but main functions include muscle control, helping the brain interpret the five senses, and controlling glands in the human body. Each cranial nerve pair controls specific functions of the human body.