splenius cervicis, one of a pair of deep muscles of the neck and back. Arising from a narrow tendinous band from the spinous processes of the third through the sixth thoracic vertebrae, it inserts into the transverse processes of the upper two or three cervical vertebrae. The muscle is innervated by the lateral branches of the dorsal primary divisions of the middle and the lower cervical nerves. The splenius cervicis acts to rotate, bend, and extend the head and neck. Also called splenius colli.
