[TA] continuous with musculus semispinalis thoracis; origin, transverse processes of second to fifth thoracic vertebrae; insertion, spinous processes of axis and third to fifth cervical vertebrae; action, extends cervical spine; nerve supply, dorsal primary rami of cervical and thoracic spinal nerves. SYN: musculus semispinalis cervicis [TA], musculus semispinalis colli*, semispinal muscle of neck.