Includes spinal cord segments C1 to C8.
The cervical spinal cord receives sensory/afferent signals from the neck and upper extremities and, via the diaphragmatic nerve, from the diaphragm muscle, pleura and pericardium.
From the cervical spinal cord, motor/efferent signals emanate to the musculature of the neck and upper limbs and to the diaphragma that is so important for inhalation.
Note that the C1 segment almost always lacks hind roots and that its front roots are relatively inconspicuous.