There are 8 pairs of cervical nerve roots that innervate the head, neck, shoulder and upper limb regions. Cervical 1 nerve roots innervate skin sensation in the temporal region and behind the ears; cervical 2 nerve roots innervate skin sensation in the upper part of the neck, the back of the head and occiput; cervical 3 nerve roots innervate skin sensation in the lower part of the neck, the front and back of the neck; and cervical 4 nerve roots innervate skin sensation in the back of the shoulder. The cervical 5 nerve root innervates the skin sensation of the back, the outer side of the upper arm, and the radial side of the forearm; the cervical 6 nerve root innervates the skin sensation of the radial side of the lower part of the arm; the cervical 7 nerve root innervates the skin sensation of the outer middle of the palm of the hand; and the cervical 8 nerve root innervates the skin sensation of the inner and outer ulnar side of the palm of the hand. If you experience any discomfort, it is recommended that you seek medical advice promptly.