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.
â¢ Roots: C7, C8.â¢ Nerve: Radial nerve, axillary nerve.â¢ Innervation Route: C7, C8 â axillary nerve â triceps brachii branch â medial triceps brachii branch â anconeus.EXAMINATIONMuscle Function: Extends the elbow. Long head assists in adduction and extension of the shoulder.esist-extension of the elbow (in the direction of forearm flexion). Resist up to the unlocked position of slight elbow flexion and not to full extension (locked elbow). â¢ Roots: C6, C7, C8, T1.â¢ Nerve: Radial nerve.â¢ Innervation Route: C6, C7, C8, T1 â radial nerve â triceps brachii.