Deep petrosal nerve is formed from
Symathetic plexus around carotid
Facial nerve
Glossopharyngeal
Internal carotid plexus
The deep petrosal nerve,sympathetic in nature is a branch of the sympathetic plexus around the internal carotid aery.It contains postganglionic fibres from the superior cervical sympathetic ganglion. Ref,BDC VOL.3,Fouh edition
Head and neck