The<unk>  (pupillary-skin reflex) consists of dilation of the ipsilateral pupil in response to pain applied to the neck, face, and upper trunk. If the right side of the neck is subjected to a painful stimulus, the right pupil dilates (increases in size 1-2mm from baseline). This reflex is absent in Horner's syndrome and lesions involving the cervical sympathetic fibers. The enhanced<unk>  in asymptomatic patients with cluster headache is due to preganglionic sympathetic mechanisms.
Ciliospinal reflex
Axon reflex
Gastrocolic reflex
Tonic labyrinthine reflex
Accommodation reflex
Bainbridge reflex
Paraspinal inhibition
Vagovagal reflex