accessory phrenic nerve

Last reviewed 01/2018

The accessory phrenic nerve on each side:

  • occurs in roughly 15-25% of people
  • originates as a branch of the fifth cervical nerve which would otherwise pass to subclavius
  • begins lateral to the phrenic nerve in the neck and obliquely traverses the anterior surface of scalenus anterior as it descends. Joins the phrenic nerve to descend to the diaphragm at the root of the neck.
  • supplies the diaphragm with somatic motor and afferent fibres