The nerve supply to the diaphragm is primarily from the phrenic nerve and particularly its C4 origin. This reflects the developmental descent of the structure from its initially cephalad position. It supplies both somatic motor and sensory fibres.
In a minority of individuals, an accessory phrenic nerve from C5 also exists.
Additionally, the portion of the diaphragm derived from the inner surface of the body wall may contribute sensory fibres to the periphery of the diaphragm. These may originate from the lower 6 or 7 intercostal nerves.
Last reviewed 01/2018