Deep petrosal nerve is formed from
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
Symathetic plexus around carotid
Facial nerve
Glossopharyngeal
Internal carotid plexus
Head and neck