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.
2-6. THE CRANIAL NERVES a. Olfactory Nerve (I). (1) Sensory nerve. (2) Transmits smell impulses from receptors in the nasal mucosa to the brain. b. Optic Nerve (II). (1) Sensory nerve. (2) Transmits visual impulses from the eye to the brain. c. Oculomotor Nerve (III). (1) Motor nerve. (2) Contracts the eyeball muscles. d. Trochlear Nerve (IV). (1) Motor nerve. (2) Contracts the eyeball muscles. e. Trigeminal Nerve (V). (1) Mixed nerve. (2) Transmits pain, touch, and temperature impulses from the face and head to the brain (sensory function). (3) Contracts the muscles of chewing (motor function). f. Abducens Nerve (VI). (1) Motor nerve. (2) Contracts eyeball muscles. g. Facial Nerve (VII). (1) Mixed nerve. (2) Transmits taste impulses from the tongue to the brain (sensory function). (3) Contracts the muscles of facial expression and stimulates secretion of salivary and lacrimal glands (motor function).